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Georgiou M, Hashem SA, Michaelides M, Chacko JG, Uwaydat SH. A patient with albinism and retinitis pigmentosa, a case report. Am J Ophthalmol Case Rep 2024; 34:102068. [PMID: 38745847 PMCID: PMC11092391 DOI: 10.1016/j.ajoc.2024.102068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Revised: 04/11/2024] [Accepted: 04/17/2024] [Indexed: 05/16/2024] Open
Abstract
Purpose To present a case of molecularly confirmed oculocutaneous albinism (OCA) and retinitis pigmentosa (RP). Observations A 46-year-old male with a lifelong established diagnosis of OCA and baseline best corrected visual acuity (BCVA) of 20/200, presented for worsening visual acuity over the last few years. BCVA was light perception and hand motion at face for the right and left eye, respectively. Fundus exam showed hypopigmented fundi with visible choroidal vessels and blunted foveal reflexes in both eyes. Optical coherence tomography showed foveal hypoplasia and outer retinal degenerative changes not typical of OCA. Fundus autofluorescence (FAF) imaging showed focal areas of decreased signal at the fovea, similar to areas of atrophy in an age matched patient with PDE6A-RP. Genetic testing identified a homozygous disease-causing variant in TYR c.1467dup, p. (Ala490Cysfs*20) causing OCA, and a homozygous pathogenic variant c.304C > A, p. (Arg102Ser) in PDE6A causing autosomal recessive RP. Conclusions and importance This is the first report of a patient with OCA and RP. The lack of pigmentary changes can make the diagnosis of RP challenging in patients with albinism. FAF can show features suggestive of RP and genetic testing can establish the diagnosis. The findings described herein may help physicians diagnose an extremely rare phenotype.
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Affiliation(s)
- Michalis Georgiou
- Jones Eye Institute, University of Arkansas for Medical Sciences, Little Rock, AR, USA
- Moorfields Eye Hospital NHS Foundation Trust, City Road, London, EC1V 2PD, UK
- UCL Institute of Ophthalmology, University College London, 11-43 Bath Street, London, EC1V 9EL, UK
| | - Shaima Awadh Hashem
- Moorfields Eye Hospital NHS Foundation Trust, City Road, London, EC1V 2PD, UK
- UCL Institute of Ophthalmology, University College London, 11-43 Bath Street, London, EC1V 9EL, UK
| | - Michel Michaelides
- Moorfields Eye Hospital NHS Foundation Trust, City Road, London, EC1V 2PD, UK
- UCL Institute of Ophthalmology, University College London, 11-43 Bath Street, London, EC1V 9EL, UK
| | - Joseph G. Chacko
- Jones Eye Institute, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Sami H. Uwaydat
- Jones Eye Institute, University of Arkansas for Medical Sciences, Little Rock, AR, USA
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Arora N, Hoyek S, Patel NA. Nystagmus and Foveal Hypoplasia in a Carrier of Oculocutaneous Albinism. Ophthalmic Surg Lasers Imaging Retina 2024; 55:349-353. [PMID: 38860972 DOI: 10.3928/23258160-20240207-03] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2024]
Abstract
We report a 23-year-old female patient with ophthalmic features of albinism, including refractive errors, nystagmus, depigmented fundus, and foveal hypoplasia. She presented for a rhegmatogenous retinal detachment, which was surgically reattached with no complications. Further genetic testing revealed the presence of a heterozygous pathogenic oculocutaneous albinism OCA2 gene mutation, conferring carrier status. To the best of our knowledge, this is the first reported case of typical ocular phenotype of albinism, specifically nystagmus, in a patient who is carrier for oculo-cutaneous albinism. Further research is required to expand the genotype-phenotype relationship in carriers of oculocutaneous albinism. [Ophthalmic Surg Lasers Imaging Retina 2024;55:349-353.].
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Tu Z, Degg C, Bach M, McLean R, Sheth V, Thomas MG, Yang S, Gottlob I, Proudlock FA. ERG Responses in Albinism, Idiopathic Infantile Nystagmus, and Controls. Invest Ophthalmol Vis Sci 2024; 65:11. [PMID: 38573619 PMCID: PMC10996992 DOI: 10.1167/iovs.65.4.11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 03/04/2024] [Indexed: 04/05/2024] Open
Abstract
Purpose Our primary aim was to compare adult full-field ERG (ffERG) responses in albinism, idiopathic infantile nystagmus (IIN), and controls. A secondary aim was to investigate the effect of within-subject changes in nystagmus eye movements on ffERG responses. Methods Dilated Ganzfeld flash ffERG responses were recorded using DTL electrodes under conditions of dark (standard and dim flash) and light adaptation in 68 participants with albinism, 43 with IIN, and 24 controls. For the primary aim, the effect of group and age on ffERG responses was investigated. For the secondary aim, null region characteristics were determined using eye movements recorded prior to ffERG recordings. ffERG responses were recorded near and away from the null regions of 18 participants also measuring the success rate of recordings. Results For the primary aim, age-adjusted photopic a- and b-wave amplitudes were consistently smaller in IIN compared with controls (P < 0.0001), with responses in both groups decreasing with age. In contrast, photopic a-wave amplitudes increased with age in albinism (P = 0.0035). For the secondary aim, more intense nystagmus significantly reduced the success rate of measurable responses. Within-subject changes in nystagmus intensity generated small, borderline significant differences in photopic b-wave peak times and a-and b-wave amplitudes under scotopic conditions with standard flash. Conclusions Age-adjusted photopic ffERG responses are significantly reduced in IIN adding to the growing body of evidence of retinal abnormalities in IIN. Differences between photopic responses in albinism and controls depend on age. Success at obtaining ffERG responses could be improved by recording responses at the null region.
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Affiliation(s)
- Zhanhan Tu
- University of Leicester Ulverscroft Eye Unit, School of Psychology and Vision Sciences, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, Leicester, United Kingdom
| | - Christopher Degg
- Medical Physics and Clinical Engineering, Nottingham University Hospitals NHS Trust, United Kingdom
| | - Michael Bach
- Eye Center, Freiburg University, Killianstraße 5, Freiburg, Germany
| | - Rebecca McLean
- University of Leicester Ulverscroft Eye Unit, School of Psychology and Vision Sciences, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, Leicester, United Kingdom
| | - Viral Sheth
- University of Leicester Ulverscroft Eye Unit, School of Psychology and Vision Sciences, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, Leicester, United Kingdom
| | - Mervyn G. Thomas
- University of Leicester Ulverscroft Eye Unit, School of Psychology and Vision Sciences, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, Leicester, United Kingdom
| | - Shangqing Yang
- Gonville and Caius College, University of Cambridge, Cambridge, United Kingdom
| | - Irene Gottlob
- University of Leicester Ulverscroft Eye Unit, School of Psychology and Vision Sciences, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, Leicester, United Kingdom
- Cooper University Hospital, Camden, United States
| | - Frank A. Proudlock
- University of Leicester Ulverscroft Eye Unit, School of Psychology and Vision Sciences, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, Leicester, United Kingdom
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Kruijt CC, de Wit GC, van Minderhout HM, Schalij-Delfos NE, van Genderen MM. Clinical and mutational characteristics of oculocutaneous albinism type 7. Sci Rep 2024; 14:7572. [PMID: 38555393 PMCID: PMC10981718 DOI: 10.1038/s41598-024-57969-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 03/23/2024] [Indexed: 04/02/2024] Open
Abstract
The purpose of this paper is to expand on the phenotype of oculocutaneous albinism type 7 (OCA7). We described three patients with OCA7: two from a consanguineous family of Kurdish origin and one patient of Dutch origin. We compared them with all patients described to date in the literature. All newly described patients had severely reduced visual acuity (VA), nystagmus, hypopigmentation of the fundus, severe foveal hypoplasia, and chiasmal misrouting. None had iris translucency. All patients had normal pigmentation of skin and hair. We found one novel mutation in the Dutch patient: c.565G > A; p.(Gly189Ser). We compared our patients to the 15 described in the literature to date. All 18 patients had substantially pigmented skin and hair, very poor VA (0.4-1.3 logMAR), nystagmus, (mild) ocular hypopigmentation, foveal hypoplasia, and misrouting. Although pigmentation levels were mildly affected in OCA7, patients had a severe ocular phenotype with VA at the poorer end of the albinism spectrum, severe foveal hypoplasia, and chiasmal misrouting. OCA7 patients had a phenotype restricted to the eyes, and similar to that of X-linked ocular albinism. We therefore propose to rename the disorder in ocular albinism type 2. Unfolding the role of LRMDA in OCA7, may bring us a step closer in identifying the responsible factors for the co-occurrence of foveal hypoplasia and misrouting.
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Affiliation(s)
- C C Kruijt
- Bartiméus Diagnostic Center for Complex Visual Disorders, Zeist, The Netherlands.
- Department of Ophthalmology, Leiden University Medical Center, J3-S, Albinusdreef 2, P.O. Box 9600, 2300 RC, Leiden, The Netherlands.
| | - G C de Wit
- Bartiméus Diagnostic Center for Complex Visual Disorders, Zeist, The Netherlands
| | - H M van Minderhout
- Department of Ophthalmology, Medical Center Haaglanden, The Hague, The Netherlands
| | - N E Schalij-Delfos
- Department of Ophthalmology, Leiden University Medical Center, J3-S, Albinusdreef 2, P.O. Box 9600, 2300 RC, Leiden, The Netherlands
| | - M M van Genderen
- Bartiméus Diagnostic Center for Complex Visual Disorders, Zeist, The Netherlands
- Department of Ophthalmology, University Medical Center Utrecht, Utrecht, The Netherlands
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Woertz EN, Ayala GD, Wynne N, Tarima S, Zacharias S, Brilliant MH, Dunn TM, Costakos D, Summers CG, Strul S, Drack AV, Carroll J. Quantitative Foveal Structural Metrics as Predictors of Visual Acuity in Human Albinism. Invest Ophthalmol Vis Sci 2024; 65:3. [PMID: 38441889 PMCID: PMC10916884 DOI: 10.1167/iovs.65.3.3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 01/03/2024] [Indexed: 03/07/2024] Open
Abstract
Purpose To assess the degree to which quantitative foveal structural measurements account for variation in best-corrected visual acuity (BCVA) in human albinism. Methods BCVA was measured and spectral domain optical coherence tomography (SD-OCT) images were acquired for 74 individuals with albinism. Categorical foveal hypoplasia grades were assessed using the Leicester Grading System for Foveal Hypoplasia. Foveal anatomical specialization (foveal versus parafoveal value) was quantified for inner retinal layer (IRL) thickness, outer segment (OS) length, and outer nuclear layer (ONL) thickness. These metrics, participant sex, and age were used to build a multiple linear regression of BCVA. This combined linear model's predictive properties were compared to those of categorical foveal hypoplasia grading. Results The cohort included three participants with type 1a foveal hypoplasia, 23 participants with type 1b, 33 with type 2, ten with type 3, and five with type 4. BCVA ranged from 0.08 to 1.00 logMAR (mean ± SD: 0.53 ± 0.21). IRL ratio, OS ratio, and ONL ratio were measured in all participants and decreased with increasing severity of foveal hypoplasia. The best-fit combined linear model included all three quantitative metrics and participant age expressed as a binary variable (divided into 0-18 years and 19 years or older; adjusted R2 = 0.500). This model predicted BCVA more accurately than a categorical foveal hypoplasia model (adjusted R2 = 0.352). Conclusions A quantitative model of foveal specialization accounts for more variance in BCVA in albinism than categorical foveal hypoplasia grading. Other factors, such as optical aberrations and eye movements, may account for the remaining unexplained variance.
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Affiliation(s)
- Erica N. Woertz
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- School of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Gelique D. Ayala
- School of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Niamh Wynne
- Department of Ophthalmology and Visual Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Sergey Tarima
- Division of Biostatistics, Institute for Health and Equity, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Serena Zacharias
- School of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Murray H. Brilliant
- Center for Precision Medicine Research, Marshfield Clinic, Marshfield, Wisconsin, United States
| | - Taylor M. Dunn
- Department of Genetics, University of Alabama at Birmingham, Birmingham, Alabama, United States
- Department of Ophthalmology and Visual Sciences, University of Iowa Hospitals and Clinics, Iowa City, Iowa, United States
| | - Deborah Costakos
- Department of Ophthalmology and Visual Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - C. Gail Summers
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, Minnesota, United States
| | - Sasha Strul
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, Minnesota, United States
| | - Arlene V. Drack
- Department of Ophthalmology and Visual Sciences, University of Iowa Hospitals and Clinics, Iowa City, Iowa, United States
| | - Joseph Carroll
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Department of Ophthalmology and Visual Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
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Sheth V, McLean RJ, Tu Z, Ather S, Gottlob I, Proudlock FA. Visual Field Deficits in Albinism in Comparison to Idiopathic Infantile Nystagmus. Invest Ophthalmol Vis Sci 2024; 65:13. [PMID: 38319668 PMCID: PMC10854418 DOI: 10.1167/iovs.65.2.13] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Accepted: 01/08/2024] [Indexed: 02/07/2024] Open
Abstract
Purpose This is the first systematic comparison of visual field (VF) deficits in people with albinism (PwA) and idiopathic infantile nystagmus (PwIIN) using static perimetry. We also compare best-corrected visual acuity (BCVA) and optical coherence tomography measures of the fovea, parafovea, and circumpapillary retinal nerve fiber layer in PwA. Methods VF testing was performed on 62 PwA and 36 PwIIN using a Humphrey Field Analyzer (SITA FAST 24-2). Mean detection thresholds for each eye were calculated, along with quadrants and central measures. Retinal layers were manually segmented in the macular region. Results Mean detection thresholds were significantly lower than normative values for PwA (-3.10 ± 1.67 dB, P << 0.0001) and PwIIN (-1.70 ± 1.54 dB, P < 0.0001). Mean detection thresholds were significantly lower in PwA compared to PwIIN (P < 0.0001) and significantly worse for left compared to right eyes in PwA (P = 0.0002) but not in PwIIN (P = 0.37). In PwA, the superior nasal VF was significantly worse than other quadrants (P < 0.05). PwIIN appeared to show a mild relative arcuate scotoma. In PwA, central detection thresholds were correlated with foveal changes in the inner and outer retina. VF was strongly correlated to BCVA in both groups. Conclusions Clear peripheral and central VF deficits exist in PwA and PwIIN, and static VF results need to be interpreted with caution clinically. Since PwA exhibit considerably lower detection thresholds compared to PwIIN, VF defects are unlikely to be due to nystagmus in PwA. In addition to horizontal VF asymmetry, PwA exhibit both vertical and interocular asymmetries, which needs further exploration.
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Affiliation(s)
- Viral Sheth
- Health Sciences School, University of Sheffield, Sheffield, Yorkshire, United Kingdom
- The University of Leicester Ulverscroft Eye Unit, Psychology and Vision Sciences, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, Leicester, United Kingdom
| | - Rebecca J. McLean
- The University of Leicester Ulverscroft Eye Unit, Psychology and Vision Sciences, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, Leicester, United Kingdom
| | - Zhanhan Tu
- The University of Leicester Ulverscroft Eye Unit, Psychology and Vision Sciences, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, Leicester, United Kingdom
| | - Sarim Ather
- Oxford University Hospitals NHS Foundation Trust, Headley Way, Headington, Oxfordshire, United Kingdom
| | - Irene Gottlob
- The University of Leicester Ulverscroft Eye Unit, Psychology and Vision Sciences, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, Leicester, United Kingdom
- Department of Neurology, Cooper University Health Care, Cooper Medical School of Rowan University, Camden, New Jersey, United States
| | - Frank A. Proudlock
- The University of Leicester Ulverscroft Eye Unit, Psychology and Vision Sciences, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, Leicester, United Kingdom
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Proudlock FA, McLean RJ, Sheth V, Ather S, Gottlob I. Phenotypic Features Determining Visual Acuity in Albinism and the Role of Amblyogenic Factors. Invest Ophthalmol Vis Sci 2024; 65:14. [PMID: 38319667 PMCID: PMC10854414 DOI: 10.1167/iovs.65.2.14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 01/05/2024] [Indexed: 02/07/2024] Open
Abstract
Albinism is a spectrum disorder causing foveal hypoplasia, nystagmus, and hypopigmentation of the iris and fundus along with other visual deficits, which can all impact vision. Albinism is also associated with amblyogenic factors which could affect monocular visual acuity. The foveal appearance in albinism can range from mild foveal hypoplasia to that which is indistinguishable from the peripheral retina. The appearance can be quickly and easily graded using the Leicester Grading System in the clinic. However, interquartile ranges of 0.3 logMAR for the grades associated with albinism limit the accuracy of the grading system in predicting vision. Here, we discuss the potential role of nystagmus presenting evidence that it may not be a major source of variability in the prediction of visual acuity. We also show that interocular differences in visual acuity are low in albinism despite high levels of amblyogenic factors indicating that active suppression of vision in one eye in albinism is uncommon.
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Affiliation(s)
- Frank A Proudlock
- The University of Leicester Ulverscroft Eye Unit, Psychology and Vision Sciences, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, Leicester, United Kingdom
| | - Rebecca J McLean
- The University of Leicester Ulverscroft Eye Unit, Psychology and Vision Sciences, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, Leicester, United Kingdom
| | - Viral Sheth
- The University of Leicester Ulverscroft Eye Unit, Psychology and Vision Sciences, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, Leicester, United Kingdom
- Health Sciences School, University of Sheffield, Sheffield, Yorkshire, United Kingdom
| | - Sarim Ather
- Oxford University Hospitals NHS Foundation Trust, Headley Way, Headington, Oxfordshire, United Kingdom
| | - Irene Gottlob
- The University of Leicester Ulverscroft Eye Unit, Psychology and Vision Sciences, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, Leicester, United Kingdom
- Department of Neurology, Cooper University Health Care, Cooper Medical School of Rowan University, Camden, New Jersey, United States
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Kerschensteiner D, Feller MB. Mapping the Retina onto the Brain. Cold Spring Harb Perspect Biol 2024; 16:a041512. [PMID: 38052498 PMCID: PMC10835620 DOI: 10.1101/cshperspect.a041512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/07/2023]
Abstract
Vision begins in the retina, which extracts salient features from the environment and encodes them in the spike trains of retinal ganglion cells (RGCs), the output neurons of the eye. RGC axons innervate diverse brain areas (>50 in mice) to support perception, guide behavior, and mediate influences of light on physiology and internal states. In recent years, complete lists of RGC types (∼45 in mice) have been compiled, detailed maps of their dendritic connections drawn, and their light responses surveyed at scale. We know less about the RGCs' axonal projection patterns, which map retinal information onto the brain. However, some organizing principles have emerged. Here, we review the strategies and mechanisms that govern developing RGC axons and organize their innervation of retinorecipient brain areas.
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Affiliation(s)
- Daniel Kerschensteiner
- Department of Ophthalmology and Visual Sciences
- Department of Neuroscience
- Department of Biomedical Engineering, Washington University School of Medicine, St. Louis, Missouri 63110, USA
| | - Marla B Feller
- Department of Molecular and Cell Biology
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, California 94720, USA
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Chen C, Li J, Wang B, Wang Y, Yu X. TYR mutation in a Chinese population with oculocutaneous albinism: Molecular characteristics and ophthalmic manifestations. Exp Eye Res 2024; 239:109761. [PMID: 38145795 DOI: 10.1016/j.exer.2023.109761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 12/07/2023] [Accepted: 12/19/2023] [Indexed: 12/27/2023]
Abstract
Oculocutaneous albinism (OCA) is a rare inherited disorder characterized by a partial or complete reduction of melanin biosynthesis that leads to hypopigmentation in the skin, hair and eyes. The OCA1 subtype is caused by mutations in TYR. The purpose of this study was to investigate the genetic and clinical ophthalmic characteristics of TYR mutations in patients with OCA. Herein, 51 probands with a clinical diagnosis of OCA were enrolled. Whole-exome sequencing and comprehensive ophthalmic examinations were performed. Overall, TYR mutations were detected in 37.3% (19/51) in the patients with OCA. Fifteen patients had compound heterozygous variants, and four cases had homozygous variants. Eleven different pathogenic variants in TYR were detected in these 19 patients, with missense, insertion, delins and nonsense in 71.1% (27/38), 15.8% (6/38), 2.6% (1/38), and 10.5% (4/38), respectively. Clinical examinations revealed that 84.2% (16/19) of patients were OCA1A, and 15.8% (3/19) were OCA1B. Most TYR probands (52.6%, 10/19) had moderate vision impairment, 15.8% (3/19) had severe visual impairment, 10.5% (2/19) exhibited blindness, only 5.3% (1/19) had mild visual impairment and 15.8% (3/19) were not available. Photophobia and nystagmus were found in 100% (19/19) of the patients. In addition, grade 4 foveal hypoplasia was detected in 100% (12/12) of the patients. In conclusion: The TYR patients exhibited severe ocular phenotypes: the majority (93.8%, 15/16) of them had a moderate vision impairment or worse, and 100% (12/12) had severe grade 4 foveal hypoplasia. These novel findings could provide insight into the understanding of OCA.
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Affiliation(s)
- Chonglin Chen
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, 510060, China
| | - Jun Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, 510060, China
| | - Bingqi Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, 510060, China
| | - Yinghuan Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, 510060, China
| | - Xinping Yu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, 510060, China.
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Yahalom C, Navarrete A, Juster A, Galbinur A, Blumenfeld A, Hendler K. Visual acuity improvement in children with albinism beyond the first decade of life. PLoS One 2024; 19:e0296744. [PMID: 38232104 DOI: 10.1371/journal.pone.0296744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2023] [Accepted: 12/19/2023] [Indexed: 01/19/2024] Open
Abstract
PURPOSE To determine if visual maturation continues beyond the first decade of life in children with albinism and whether this is related to albinism type, presence of nystagmus, eye muscle surgery or refractive errors. DESIGN Case series based on retrospective study of children with confirmed genetic diagnosis of albinism. METHODS Clinical data were obtained from medical files of children examined during school years, including albinism type, visual acuity, eye muscle surgery, nystagmus, and others on different visits (Visit 1: ages 7-9; Visit 2: ages: 10-12; Visit 3: ages 13-16; Visit 4: ages >16). RESULTS Seventy-five children with albinism were included in the study. Patients were divided into different groups according to the albinism type including OCA1A: 17; OCA1B: 28; OCA2: 26; HPS: 3; OCA4: 1. Follow-up ranged from 3-13 years. Progressive visual acuity improvement was seen in all three main groups. T-test paired samples showed a statistically significant improvement when comparing vision from Visit 1 and Visit 3 in both OCA1A and OCA2 groups, with a mean vision improvement of 2 lines. There was no correlation between visual improvement and refractive error, eye muscle surgery or nystagmus. CONCLUSION An improved visual performance was seen in a large percentage of children with albinism during the second decade of life. The reason for this late improvement in vision is not clear but may be related to late foveal maturation or improvement in nystagmus with time. This information is useful for clinicians of these patients and when counseling parents.
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Affiliation(s)
- Claudia Yahalom
- Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
- Department of Ophthalmology, Hadassah Medical Center, Jerusalem, Israel
| | - Ana Navarrete
- Department of Ophthalmology, Hadassah Medical Center, Jerusalem, Israel
| | - Atara Juster
- Department of Ophthalmology, Hadassah Medical Center, Jerusalem, Israel
| | - Ayan Galbinur
- Department of Ophthalmology, Hadassah Medical Center, Jerusalem, Israel
| | - Anat Blumenfeld
- Department of Ophthalmology, Hadassah Medical Center, Jerusalem, Israel
| | - Karen Hendler
- Department of Ophthalmology, Hadassah Medical Center, Jerusalem, Israel
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Kessel L, Kjølholm CDB, Jordana JT. Does Foveal Hypoplasia Affect Emmetropization in Patients with Albinism? CHILDREN (BASEL, SWITZERLAND) 2023; 10:1910. [PMID: 38136112 PMCID: PMC10741917 DOI: 10.3390/children10121910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2023] [Revised: 12/07/2023] [Accepted: 12/08/2023] [Indexed: 12/24/2023]
Abstract
(1) Background: The aim of the study was to describe refractive development from early childhood to adulthood in Danish patients with albinism and to evaluate the effect of foveal developmental stage on refractive development; (2) Methods: Patients with a clinical diagnosis of ocular or oculocutaneous albinism were invited for a refractive evaluation and comprehensive phenotyping including macular optical coherence tomography (OCT) scans. Foveal hypoplasia was graded based on OCT from 0 (normal) to 4 (absence of any signs of foveal specialization). Medical files were reviewed for historical refractive values in individual patients; (3) Results: Hyperopia (spherical equivalent refraction (SEQ) of ≥+1 Diopter (D)) was common in both children (81.3%) and adults (67.1%). The lower prevalence of hyperopia in adults was predominantly explained by increasing astigmatism with age. Emmetropization (>2D change from before 3 years to adolescence) was seen in 22.2%. There was no influence on foveal hypoplasia grade on the degree of refractive errors throughout life; (4) Conclusions: We found that emmetropization was uncommon in Danish patients with albinism and that the degree of foveal developmental stage did not influence emmetropization or the distribution of refractive errors. High degrees of hyperopia and astigmatism were common. These results indicate that fear of impeding emmetropization should not refrain the clinician from providing adequate correction for refractive errors in young children with albinism.
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Affiliation(s)
- Line Kessel
- Department of Ophthalmology, Copenhagen University Hospital—Rigshospitalet, 2100 Copenhagen, Denmark; (C.D.B.K.); (J.T.J.)
- Department of Clinical Medicine, University of Copenhagen, 2200 Copenhagen, Denmark
| | | | - Joaquim Torner Jordana
- Department of Ophthalmology, Copenhagen University Hospital—Rigshospitalet, 2100 Copenhagen, Denmark; (C.D.B.K.); (J.T.J.)
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12
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Talsma HE, Kruijt CC, de Wit GC, Zwerver SHL, van Genderen MM. Nystagmus Characteristics in Albinism: Unveiling the Link to Foveal Hypoplasia and Visual Acuity. Invest Ophthalmol Vis Sci 2023; 64:30. [PMID: 38133506 PMCID: PMC10746925 DOI: 10.1167/iovs.64.15.30] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Accepted: 11/21/2023] [Indexed: 12/23/2023] Open
Abstract
Purpose The purpose of this study was to describe the association among nystagmus characteristics, foveal hypoplasia, and visual acuity in patients with albinism. Methods We studied nystagmus recordings of 50 patients with albinism. The nystagmus waveform was decomposed into two types: dominantly pendular and dominantly jerk. We correlated the nystagmus type, amplitude, frequency, and percentage of low velocity (PLOV) to Snellen visual acuity and foveal hypoplasia grades. Results The grade of foveal hypoplasia and visual acuity showed a strong correlation (r = 0.87, P < 0.0001). Nystagmus type and PLOV had the strongest significant (P < 0.0001) correlation with visual acuity (r = 0.70 and r = -0.56, respectively) and with foveal hypoplasia (r = 0.76 and r = -0.60, respectively). Patients with pendular nystagmus type had the lowest PLOV, and the highest grade of foveal hypoplasia (P < 0.0001). Severe foveal hypoplasia (grade 4), was almost invariably associated with pendular nystagmus (86%). Conclusions Foveal hypoplasia grade 4 is associated with pendular nystagmus, lower PLOV, and worse visual acuity. Based on these results, nystagmus recordings at a young age may contribute to predicting visual outcomes.
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Affiliation(s)
- Herman E. Talsma
- Bartiméus Diagnostic Center for Complex Visual Disorders, Zeist, The Netherlands
| | - Charlotte C. Kruijt
- Bartiméus Diagnostic Center for Complex Visual Disorders, Zeist, The Netherlands
- Department of Ophthalmology, Leiden University Medical Center, Leiden, The Netherlands
| | - Gerard C. de Wit
- Bartiméus Diagnostic Center for Complex Visual Disorders, Zeist, The Netherlands
| | - Stefan H. L. Zwerver
- Bartiméus Diagnostic Center for Complex Visual Disorders, Zeist, The Netherlands
- Department of Cognitive Neuroscience, Donders Institute for Brain, Cognition and Behaviour, Radboudumc, Nijmegen, The Netherlands
| | - Maria M. van Genderen
- Bartiméus Diagnostic Center for Complex Visual Disorders, Zeist, The Netherlands
- Department of Ophthalmology, University Medical Center Utrecht, Utrecht, The Netherlands
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13
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Sergouniotis PI, Michaud V, Lasseaux E, Campbell C, Plaisant C, Javerzat S, Birney E, Ramsden SC, Black GC, Arveiler B. A multilayered approach to the analysis of genetic data from individuals with suspected albinism. J Med Genet 2023; 60:1245-1249. [PMID: 37460203 DOI: 10.1136/jmg-2022-109088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Accepted: 05/12/2023] [Indexed: 11/29/2023]
Abstract
Albinism is a clinically and genetically heterogeneous group of conditions characterised by visual abnormalities and variable degrees of hypopigmentation. Multiple studies have demonstrated the clinical utility of genetic investigations in individuals with suspected albinism. Despite this, the variation in the provision of genetic testing for albinism remains significant. One key issue is the lack of a standardised approach to the analysis of genomic data from affected individuals. For example, there is variation in how different clinical genetic laboratories approach genotypes that involve incompletely penetrant alleles, including the common, 'hypomorphic' TYR c.1205G>A (p.Arg402Gln) [rs1126809] variant. Here, we discuss the value of genetic testing as a frontline diagnostic tool in individuals with features of albinism and propose a practice pattern for the analysis of genomic data from affected families.
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Affiliation(s)
- Panagiotis I Sergouniotis
- Division of Evolution, Infection and Genomics, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
- European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL- EBI), Wellcome Genome Campus, Cambridge, UK
- Manchester Centre for Genomic Medicine, Saint Mary's Hospital, Manchester University NHS Foundation Trust, Manchester, UK
- Manchester Royal Eye Hospital, Manchester University NHS Foundation Trust, Manchester, UK
| | - Vincent Michaud
- Department of Medical Genetics, University Hospital of Bordeaux, Bordeaux, France
- INSERM U1211, Rare Diseases, Genetics and Metabolism, University of Bordeaux, Bordeaux, France
| | - Eulalie Lasseaux
- Department of Medical Genetics, University Hospital of Bordeaux, Bordeaux, France
| | - Christopher Campbell
- Manchester Centre for Genomic Medicine, Saint Mary's Hospital, Manchester University NHS Foundation Trust, Manchester, UK
| | - Claudio Plaisant
- Department of Medical Genetics, University Hospital of Bordeaux, Bordeaux, France
| | - Sophie Javerzat
- INSERM U1211, Rare Diseases, Genetics and Metabolism, University of Bordeaux, Bordeaux, France
| | - Ewan Birney
- European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL- EBI), Wellcome Genome Campus, Cambridge, UK
| | - Simon C Ramsden
- Manchester Centre for Genomic Medicine, Saint Mary's Hospital, Manchester University NHS Foundation Trust, Manchester, UK
| | - Graeme C Black
- Division of Evolution, Infection and Genomics, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
- Manchester Centre for Genomic Medicine, Saint Mary's Hospital, Manchester University NHS Foundation Trust, Manchester, UK
| | - Benoit Arveiler
- Department of Medical Genetics, University Hospital of Bordeaux, Bordeaux, France
- INSERM U1211, Rare Diseases, Genetics and Metabolism, University of Bordeaux, Bordeaux, France
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Al-Nosairy KO, Quanz EV, Eick CM, Hoffmann MB, Kornmeier J. Altered Perception of the Bistable Motion Quartet in Albinism. Invest Ophthalmol Vis Sci 2023; 64:39. [PMID: 38015177 PMCID: PMC10691394 DOI: 10.1167/iovs.64.14.39] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 10/31/2023] [Indexed: 11/29/2023] Open
Abstract
Purpose Perception of the motion quartet (MQ) alternates between horizontal and vertical motion, with a bias toward vertical motion. This vertical bias has been explained by the dominance of intrahemispheric processing. In albinism, each hemisphere receives input from both visual hemifields owing to enhanced crossing of the optic nerves at the optic chiasm. This might affect the perception of the ambiguous MQ and particularly the vertical bias. Methods The effect of optic nerve misrouting in persons with albinism and nystagmus (PWA, n = 14) on motion perception for MQ was compared with healthy controls (HC; n = 11) and with persons with nystagmus in the absence of optic nerve misrouting (PWN; n = 12). We varied the ratio of horizontal and vertical distances of MQ dots (aspect ratio [AR]) between 0.75 and 1.25 and compared the percentages of horizontal and vertical motion percepts as a function of AR between groups. Results For HC, the probability of vertical motion perception increased as a sigmoid function with increasing AR exhibiting the expected vertical percept bias (mean, 58%; median, 54%; vertical motion percepts). PWA showed a surprisingly strong horizontal bias independent of the AR with a mean of 11% (median, 10%) vertical motion percepts. The PWN was in between PWA and HC, with a mean of 34% (median, 47%) vertical perception. Nystagmus alone is unlikely to explain this pattern of results because PWA and PWN had comparable fixation stabilities. Conclusions The strong horizontal bias observed in PWA and PWN might partly result from the horizontal nystagmus. The even stronger horizontal bias in PWA indicates that the intrahemispherical corepresentation of both visual hemifields may play an additional role. The altered perception of the MQ in PWA opens opportunities to (i) understand the interplay of stability and plasticity in altered visual pathway conditions and (ii) identify visual pathway abnormalities with a perception-based test using the MQ.
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Affiliation(s)
| | - Elisabeth V. Quanz
- Department of Ophthalmology, Otto-von-Guericke University, Magdeburg, Germany
| | - Charlotta M. Eick
- Department of Ophthalmology, Otto-von-Guericke University, Magdeburg, Germany
| | - Michael B. Hoffmann
- Department of Ophthalmology, Otto-von-Guericke University, Magdeburg, Germany
- Center for Behavioral Brain Sciences, Otto-von-Guericke University, Magdeburg, Germany
| | - Jürgen Kornmeier
- Institute for Frontier Areas of Psychology and Mental Health, Freiburg, Germany
- Department of Psychiatry and Psychotherapy, Medical Center, University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
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15
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Puzniak RJ, Prabhakaran GT, McLean RJ, Stober S, Ather S, Proudlock FA, Gottlob I, Dineen RA, Hoffmann MB. CHIASM-Net: Artificial Intelligence-Based Direct Identification of Chiasmal Abnormalities in Albinism. Invest Ophthalmol Vis Sci 2023; 64:14. [PMID: 37815506 PMCID: PMC10573586 DOI: 10.1167/iovs.64.13.14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 09/06/2023] [Indexed: 10/11/2023] Open
Abstract
Purpose Albinism is a congenital disorder affecting pigmentation levels, structure, and function of the visual system. The identification of anatomical changes typical for people with albinism (PWA), such as optic chiasm malformations, could become an important component of diagnostics. Here, we tested an application of convolutional neural networks (CNNs) for this purpose. Methods We established and evaluated a CNN, referred to as CHIASM-Net, for the detection of chiasmal malformations from anatomic magnetic resonance (MR) images of the brain. CHIASM-Net, composed of encoding and classification modules, was developed using MR images of controls (n = 1708) and PWA (n = 32). Evaluation involved 8-fold cross validation involving accuracy, precision, recall, and F1-score metrics and was performed on a subset of controls and PWA samples excluded from the training. In addition to quantitative metrics, we used Explainable AI (XAI) methods that granted insights into factors driving the predictions of CHIASM-Net. Results The results for the scenario indicated an accuracy of 85 ± 14%, precision of 90 ± 14% and recall of 81 ± 18%. XAI methods revealed that the predictions of CHIASM-Net are driven by optic-chiasm white matter and by the optic tracts. Conclusions CHIASM-Net was demonstrated to use relevant regions of the optic chiasm for albinism detection from magnetic resonance imaging (MRI) brain anatomies. This indicates the strong potential of CNN-based approaches for visual pathway analysis and ultimately diagnostics.
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Affiliation(s)
- Robert J Puzniak
- Visual Processing Lab, Department of Ophthalmology, Otto-von-Guericke-University, Magdeburg, Germany
- Department of Neuroscience, Psychology, and Behaviour, University of Leicester, Leicester, United Kingdom
| | - Gokulraj T Prabhakaran
- Visual Processing Lab, Department of Ophthalmology, Otto-von-Guericke-University, Magdeburg, Germany
| | - Rebecca J McLean
- University of Leicester Ulverscroft Eye Unit, University of Leicester, Leicester Royal Infirmary, Leicester, United Kingdom
| | - Sebastian Stober
- Artificial Intelligence Lab, Institute for Intelligent Cooperating Systems, Otto-von-Guericke-University, Magdeburg, Germany
| | - Sarim Ather
- Department of Radiology, John Radcliffe Hospital, Oxford University Hospitals NHS Foundation Trust, Headington, Oxford, United Kingdom
| | - Frank A Proudlock
- University of Leicester Ulverscroft Eye Unit, University of Leicester, Leicester Royal Infirmary, Leicester, United Kingdom
| | - Irene Gottlob
- University of Leicester Ulverscroft Eye Unit, University of Leicester, Leicester Royal Infirmary, Leicester, United Kingdom
- Cooper Neurological Institute and Cooper Medical School of Rowan University, Camden, New Jersey, United States
| | - Robert A Dineen
- Mental Health and Clinical Neuroscience, Faculty of Medicine and Health Sciences, University of Nottingham, Nottingham, United Kingdom
- NIHR Nottingham Biomedical Research Centre, Nottingham, United Kingdom
| | - Michael B Hoffmann
- Visual Processing Lab, Department of Ophthalmology, Otto-von-Guericke-University, Magdeburg, Germany
- Center for Behavioral Brain Sciences, Otto-von-Guericke-Universität, Magdeburg, Germany
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16
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Lisbjerg K, Jordana JT, Brandt VN, Kjølholm C, Kessel L. Vision-Related Quality of Life in Danish Patients with Albinism and the Impact of an Updated Optical Rehabilitation. J Clin Med 2023; 12:5451. [PMID: 37685518 PMCID: PMC10488237 DOI: 10.3390/jcm12175451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 08/10/2023] [Accepted: 08/21/2023] [Indexed: 09/10/2023] Open
Abstract
(1) Background: Albinism is characterized by a lack of pigment in eyes, hair, and skin and developmental changes in the eye such as foveal hypoplasia. Patients require optical rehabilitation due to low vision, refractive errors, and photosensitivity. We aimed to assess vision-related quality of life in patients with albinism and to evaluate how this was affected by optical rehabilitation. (2) Methods: Patients with ocular or oculocutaneous albinism were invited for the study. Free-of-charge optical rehabilitation was provided as needed, including filters, glasses for near or distance, contact lenses, magnifiers or binoculars. Vision-related quality of life was assessed prior to and after optical rehabilitation using the visual function questionnaire (VFQ39) and the effect of optical rehabilitation was evaluated after accounting for age, gender, and visual acuity. (3) Results: Seventy-eight patients filled out the VFQ39 at the initial visit. Fifty patients (64.1%) returned the questionnaire 3-6 months after optical rehabilitation. The mean age of included patients was 35.9 years (standard deviation 16.6), and their best corrected distance visual acuity was 56 ETDRS letters (range 3-81). The VFQ39 composite score improved significantly from a median of 62.5 (range 14.2-77.0) to 76.5 (20.6-99.6). Significant improvements were seen for ocular pain, social functioning, mental health, role difficulties, and dependency, whereas self-assessed distance or near visual functions did not change. (4) Conclusions: Optical rehabilitation improved the self-reported vision-related quality of life in Danish patients with albinism on a number of parameters related to leading an independent and worry-free life, whereas visual improvement for distance and near tasks was likely limited by the nature of the disease and by the fact that most patients already had access to some optical aids prior to the study.
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Affiliation(s)
- Kristian Lisbjerg
- Department of Ophthalmology, Copenhagen University Hospital—Righospitalet, 2600 Glostrup, Denmark; (K.L.); (J.T.J.); (V.N.B.); (C.K.)
| | - Joaquim Torner Jordana
- Department of Ophthalmology, Copenhagen University Hospital—Righospitalet, 2600 Glostrup, Denmark; (K.L.); (J.T.J.); (V.N.B.); (C.K.)
| | - Vibeke N. Brandt
- Department of Ophthalmology, Copenhagen University Hospital—Righospitalet, 2600 Glostrup, Denmark; (K.L.); (J.T.J.); (V.N.B.); (C.K.)
| | - Christine Kjølholm
- Department of Ophthalmology, Copenhagen University Hospital—Righospitalet, 2600 Glostrup, Denmark; (K.L.); (J.T.J.); (V.N.B.); (C.K.)
| | - Line Kessel
- Department of Ophthalmology, Copenhagen University Hospital—Righospitalet, 2600 Glostrup, Denmark; (K.L.); (J.T.J.); (V.N.B.); (C.K.)
- Department of Clinical Medicine, University of Copenhagen, 2200 Copenhagen N, Denmark
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17
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Kuht HJ, Thomas MG, McLean RJ, Sheth V, Proudlock FA, Gottlob I. Abnormal foveal morphology in carriers of oculocutaneous albinism. Br J Ophthalmol 2023; 107:1202-1208. [PMID: 35379600 PMCID: PMC10359511 DOI: 10.1136/bjophthalmol-2020-318192] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 03/18/2022] [Indexed: 01/04/2023]
Abstract
BACKGROUND/AIMS To investigate the foveal morphology in carriers of oculocutaneous albinism (OCA) using spectral domain optical coherence tomography (SD-OCT). A cross-sectional, observational study. METHODS Handheld SD-OCT (Envisu C2300) was used to acquire horizontal scans through the centre of the fovea in biological parents of patients with OCA (n=28; mean age±SD=40.43±8.07 years) and age-matched and ethnicity-matched controls (n=28; mean age±SD=38.04±10.27 years). Sequence analysis was performed for variants in known genes associated with OCA. Best-corrected visual acuity (BCVA), presence of foveal hypoplasia and grade, foveal, parafoveal and perifoveal thickness measurements of total retinal layers (TRL), inner retinal layers (IRL) and outer retinal layers (ORL) thickness were measured. RESULTS Foveal hypoplasia was identified in 32.14% of OCA carriers; grade 1 in all cases. OCA carriers demonstrated significant thicker TRL thickness (median difference: 13.46 µm, p=0.009) and IRL thickness (mean difference: 8.98 µm, p<0.001) at the central fovea compared with controls. BCVA of carriers was between -0.16 and 0.18 logMAR (mean: 0.0 logMAR). No significant differences in BCVA was noted between OCA carriers or controls (p=0.83). In the OCA carriers, we identified previously reported pathogenic variants in TYR, OCA2 and SLC45A2, novel OCA2 variants (n=3) and heterozygosity of the pathogenic TYR haplotype. CONCLUSION We have, for the first time, identified foveal abnormalities in OCA carriers. This provides clinical value, particularly in cases where limited phenotype data are available. Our findings raise the possibility that previously reported mild cases of foveal hypoplasia or isolated foveal hypoplasia could correspond to OCA carrier status.
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Affiliation(s)
- Helen J Kuht
- Ulverscroft Eye Unit, Neuroscience, Psychology and Behaviour, University of Leicester, Leicester, UK
| | - Mervyn G Thomas
- Ulverscroft Eye Unit, Neuroscience, Psychology and Behaviour, University of Leicester, Leicester, UK
| | - Rebecca J McLean
- Ulverscroft Eye Unit, Neuroscience, Psychology and Behaviour, University of Leicester, Leicester, UK
| | - Viral Sheth
- Ulverscroft Eye Unit, Neuroscience, Psychology and Behaviour, University of Leicester, Leicester, UK
| | - Frank A Proudlock
- Ulverscroft Eye Unit, Neuroscience, Psychology and Behaviour, University of Leicester, Leicester, UK
| | - Irene Gottlob
- Ulverscroft Eye Unit, Neuroscience, Psychology and Behaviour, University of Leicester, Leicester, UK
- Cooper Medical School of Rowan University, Cooper Neurological Institute, Camden, New Jersey, USA
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18
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Montijn JS, Riguccini V, Levelt CN, Heimel JA. Impaired Direction Selectivity in the Nucleus of the Optic Tract of Albino Mice. Invest Ophthalmol Vis Sci 2023; 64:9. [PMID: 37548962 PMCID: PMC10411648 DOI: 10.1167/iovs.64.11.9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 07/17/2023] [Indexed: 08/08/2023] Open
Abstract
Purpose Human albinos have a low visual acuity. This is partially due to the presence of spontaneous erroneous eye movements called pendular nystagmus. This nystagmus is present in other albino vertebrates and has been hypothesized to be caused by aberrant wiring of retinal ganglion axons to the nucleus of the optic tract (NOT), a part of the accessory optic system involved in the optokinetic response to visual motion. The NOT in pigmented rodents is preferentially responsive to ipsiversive motion (i.e., motion in the contralateral visual field in the temporonasal direction). We compared the response to visual motion in the NOT of albino and pigmented mice to understand if motion coding and preference are impaired in the NOT of albino mice. Methods We recorded neuronal spiking activity with Neuropixels probes in the visual cortex and NOT in C57BL/6JRj mice (pigmented) and DBA/1JRj mice with oculocutaneous albinism (albino). Results We found that in pigmented mice, NOT is retinotopically organized, and neurons are direction tuned, whereas in albino mice, neuronal tuning is severely impaired. Neurons in the NOT of albino mice do not have a preference for ipsiversive movement. In contrast, neuronal tuning in visual cortex was preserved in albino mice and did not differ significantly from the tuning in pigmented mice. Conclusions We propose that excessive interhemispheric crossing of retinal projections in albinos may cause the disrupted left/right direction encoding we found in NOT. This, in turn, impairs the normal horizontal optokinetic reflex and leads to pendular albino nystagmus.
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Affiliation(s)
- Jorrit S. Montijn
- Department of Circuits, Structure & Function, Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Amsterdam, the Netherlands
| | - Valentina Riguccini
- Department of Molecular Visual Plasticity, Netherlands Institute for Neuroscience, Amsterdam, the Netherlands
| | - Christiaan N. Levelt
- Department of Molecular Visual Plasticity, Netherlands Institute for Neuroscience, Amsterdam, the Netherlands
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, VU University Amsterdam, Amsterdam, the Netherlands
| | - J. Alexander Heimel
- Department of Circuits, Structure & Function, Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Amsterdam, the Netherlands
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Galli J, Loi E, Dusi L, Pasini N, Rossi A, Scaglioni V, Mauri L, Fazzi E. Oculocutaneous albinism: the neurological, behavioral, and neuro-ophthalmological perspective. Eur J Pediatr 2023:10.1007/s00431-023-04938-w. [PMID: 37009951 PMCID: PMC10257606 DOI: 10.1007/s00431-023-04938-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 03/11/2023] [Accepted: 03/15/2023] [Indexed: 04/04/2023]
Abstract
Oculocutaneous albinism (OCA) is a group of rare, genetic disorders caused by absent/reduced melanin biosynthesis. The aim of this study was to explore the neurovisual, cognitive, adaptive, and behavioral profile of children affected by OCA, also evaluating any possible effect of the visual acuity deficit on the clinical profile and genotype-phenotype correlations. Eighteen children (9 males, mean age 84 months ± 41; range 18-181 months) with a molecular confirmed diagnosis of OCA were enrolled in the study. We collected data on clinical history, neurodevelopmental profile, neurological and neurovisual examination, and cognitive, adaptive, and emotional/behavioral functioning. A global neurodevelopmental impairment was detected in 56% of the children, without evolving into an intellectual disability. All the patients showed signs and symptoms of visual impairment. Low adaptive functioning was observed in 3 cases (17%). A risk for internalizing behavioral problems was documented in 6 cases (33%), for externalizing problems in 2 (11%), and for both in 5 (28%). Twelve children (67%) showed one or more autistic-like features. Correlation analyses revealed significant associations between the visual acuity level and performance intelligence quotient (p = 0.001), processing speed index (p = 0.021), Vineland total score (p = 0.020), Vineland communication (p = 0.020), and socialization (p = 0.037) domains. No significant correlations were found between genotype and phenotype. CONCLUSION Children with OCA may present a global neurodevelopmental delay that seems to improve with age and emotional/behavioral difficulties, along with the well-known visual impairment. An early neuropsychiatric evaluation and habilitative training are recommended to improve vision-related performance, neurodevelopment, and any psychological difficulties. WHAT IS KNOWN • Children with oculocutaneous albinism show dermatological and ophthalmological problems. • An early visual impairment may have negative implications on motor, emotional, and cognitive processes that would allow the child to organize his or her experiences. WHAT IS NEW • In addition to a variable combination of ocular signs and symptoms, children with oculocutaneous albinism may present an early neurodevelopmental delay and emotional/behavioral difficulties. • An early visual treatment is recommended to improve vision-related performance, neurodevelopment, and any psychological difficulties.
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Affiliation(s)
- Jessica Galli
- Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy.
- Unit of Child Neurology and Psychiatry, ASST Spedali Civili of Brescia, Brescia, Italy.
| | - Erika Loi
- Unit of Child Neurology and Psychiatry, ASST Spedali Civili of Brescia, Brescia, Italy
- Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Laura Dusi
- Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
| | - Nadia Pasini
- Department of Neurological and Vision Sciences, ASST Spedali Civili of Brescia, Brescia, Italy
| | - Andrea Rossi
- Unit of Child Neurology and Psychiatry, ASST Spedali Civili of Brescia, Brescia, Italy
| | - Vera Scaglioni
- Unit of Child Neurology and Psychiatry, ASST Spedali Civili of Brescia, Brescia, Italy
| | - Lucia Mauri
- Medical Genetics Unit, Department of Laboratory Medicine, ASST Grande Ospedale Metropolitano Niguarda, Milan, Italy
| | - Elisa Fazzi
- Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
- Unit of Child Neurology and Psychiatry, ASST Spedali Civili of Brescia, Brescia, Italy
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20
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Arcot Sadagopan K, Teng CH, Hui G, Lin DL. Ocular findings and a comparative study of hair, skin and iris color in Chinese patients with albinism. Ophthalmic Genet 2023; 44:54-69. [PMID: 36316991 DOI: 10.1080/13816810.2022.2135109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Oculocutaneous albinism (OCA) could be either non-syndromic or syndromic. There are significant challenges in clinically recognizing and differentiating Hermansky-Pudlak syndrome (HPS) from non-syndromic OCA. MATERIALS AND METHODS In a prospective consecutive case series, 63 patients (less than 18 years old) with a molecular genetic diagnosis of albinism (except OCA1A), Ocular albinism (OA) and Hermansky-Pudlak syndrome seen over a 3-year period were evaluated and analyzed. Hair colour, iris colour was graded, compared and correlated with the degree of fundus pigmentation and foveal development. RESULTS A total of 63 patients were evaluated. Forty-five patients had non-syndromic OCA (11 OCA1B, 24 OCA2, 9 OCA4, and 1 OCA6), 5 patients had OA and 13 patients had HPS. All 3 BLOC-related HPS categories were seen (1 with BLOC1, 7 with BLOC-2 and 5 with BLOC-3 related HPS). All patients with OA were hyperopic, had darker fundus pigmentation, but had poor foveal development. All HPS patients had lighter fundus pigmentation. The degree of fundus pigmentation correlated positively with the iris pigmentation and also with the foveal development only in OCA2. CONCLUSIONS Careful observation of the phenotype by comparison of the skin, hair, iris colour, with the degree of fundus pigmentation and foveal development may help clinically differentiate HPS from OCA patients of Chinese ethnicity even in the absence of any bleeding tendency.
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Affiliation(s)
- Karthikeyan Arcot Sadagopan
- Pediatric Ophthalmology & Ocular Genetics, C-MER (Shenzhen) Dennis Lam Eye Hospital, Shenzhen, China.,Honorary consultant -Lumbini Eye Institute, Shree Rana Ambika Shah Eye Hospital, Rupandehi, Bhairahawa, Nepal.,Visiting Volunteer Faculty, Department of Pediatric Ophthalmology and Adult Strabismus, Aravind Eye Hospital, Madurai, India
| | - Chih-Hao Teng
- Attending doctor, Pediatric ophthalmology & Ocular Genetics, C-MER (Shenzhen) Dennis Lam Eye Hospital, Shenzhen, China
| | - Gong Hui
- Ophthalmologist, Pediatric ophthalmology & Ocular Genetics, C-MER (Shenzhen) Dennis Lam Eye Hospital, Shenzhen, China.,Low vision department, Shenzhen Eye Hospital, Shenzhen, China
| | - Ding Ling Lin
- Pediatric Ophthalmology & Ocular Genetics, C-MER (Shenzhen) Dennis Lam Eye Hospital, Shenzhen, China
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21
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Lee H, Purohit R, Sheth V, Maconachie G, Tu Z, Thomas MG, Pilat A, McLean RJ, Proudlock FA, Gottlob I. Retinal Development in Infants and Young Children With Albinism: Evidence for Plasticity in Early Childhood. Am J Ophthalmol 2023; 245:202-211. [PMID: 36084688 DOI: 10.1016/j.ajo.2022.08.028] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 08/23/2022] [Accepted: 08/23/2022] [Indexed: 11/13/2022]
Abstract
MEETING PRESENTATION Presented at the 2016 Association for Research in Vision and Ophthalmology meeting and at the 2015 British Isles Paediatric, Ophthalmology and Strabismus Association meeting. PURPOSE To investigate the time course of foveal development after birth in infants with albinism. DESIGN Prospective, comparative cohort optical coherence tomography study. METHODS Thirty-six children with albinism were recruited. All participants were between 0 and 6 years of age and were seen at Leicester Royal Infirmary. A total of 181 mixed cross-sectional and longitudinal optical coherence tomography examinations were obtained, which were analyzed for differences in retinal development in comparison to 297 cross-sectional control examinations. RESULTS Normal retinal development involves migration of the inner retinal layers (IRLs) away from the fovea, migration of the cone photoreceptors into the fovea, and elongation of the outer retinal layers (ORLs) over time. In contrast to controls where IRL migration from the fovea was almost completed at birth, a significant degree of IRL migration was taking place after birth in albinism, before arresting prematurely at 40 months postmenstrual age (PMA). This resulted in a significantly thicker central macular thickness in albinism (Δ = 83.8 ± 6.1, P < .0001 at 69 months PMA). There was evidence of ongoing foveal ORL elongation in albinism, although reduced in amplitude compared with control subjects after 21 months PMA (Δ = -17.3 ± 4.3, P < .0001). CONCLUSIONS We have demonstrated evidence of ongoing retinal development in young children with albinism, albeit at a reduced rate and magnitude compared with control subjects. The presence of a period of retinal plasticity in early childhood raises the possibility that treatment modalities, which aim to improve retinal development, could potentially optimize visual function in albinism.
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Affiliation(s)
- Helena Lee
- From the University of Leicester Ulverscroft Eye Unit, Leicester Royal Infirmary, Leicester, United Kingdom.
| | - Ravi Purohit
- From the University of Leicester Ulverscroft Eye Unit, Leicester Royal Infirmary, Leicester, United Kingdom
| | - Viral Sheth
- From the University of Leicester Ulverscroft Eye Unit, Leicester Royal Infirmary, Leicester, United Kingdom
| | - Gail Maconachie
- From the University of Leicester Ulverscroft Eye Unit, Leicester Royal Infirmary, Leicester, United Kingdom
| | - Zhanhan Tu
- From the University of Leicester Ulverscroft Eye Unit, Leicester Royal Infirmary, Leicester, United Kingdom
| | - Mervyn G Thomas
- From the University of Leicester Ulverscroft Eye Unit, Leicester Royal Infirmary, Leicester, United Kingdom
| | - Anastasia Pilat
- From the University of Leicester Ulverscroft Eye Unit, Leicester Royal Infirmary, Leicester, United Kingdom
| | - Rebecca J McLean
- From the University of Leicester Ulverscroft Eye Unit, Leicester Royal Infirmary, Leicester, United Kingdom
| | - Frank A Proudlock
- From the University of Leicester Ulverscroft Eye Unit, Leicester Royal Infirmary, Leicester, United Kingdom
| | - Irene Gottlob
- From the University of Leicester Ulverscroft Eye Unit, Leicester Royal Infirmary, Leicester, United Kingdom
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22
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Lejoyeux R, Alonso AS, Lafolie J, Michaud V, Lasseaux E, Vasseur V, Derrien S, Robert MP, Le Mer Y, Tadayoni R, Arveiler B, Mauget-Faÿsse M. Foveal hypoplasia in parents of patients with albinism. Ophthalmic Genet 2022; 43:817-823. [PMID: 36098180 DOI: 10.1080/13816810.2022.2121841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
BACKGROUND Albinism is a group of genetic disorders characterized by general skin and retinal hypopigmentation. It is in most cases an autosomal recessive condition. Foveal hypoplasia (FH) is one of the main criteria for the diagnosis of albinism. The aim of this study was to analyze the macular profile of the parents of patients with albinism. METHODS This study included a case series of 27 patients with albinism seen in Rothschild Foundation between April 2017 and February 2020. Spectral-domain optical coherence tomography (SD-OCT) and OCT angiography (OCT-A) were performed in every patient when possible and in every available parents. FH was graded according to Thomas' classification based on OCT. Next generation sequencing-based gene panel testing was performed in parents and children when a FH was detected on OCT in a parent. RESULTS Twenty-seven patients with albinism were examined. Nine parents had FH based on the OCT B-scan (33%). In parents without FH based on the SD-OCT B-scan (67%), OCT-A showed a reduced avascular zone in the deep vascular plexus in 4 parents. Six parents carried variants that could explain their phenotype, including TYR R402Q hypomorphic alleles. CONCLUSION This study showed the presence of FH in parents of patients with albinism, and aimed to genetically explain this phenotype.
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Affiliation(s)
- R Lejoyeux
- Departement of Retina, Rothschild Foundation hospital, Paris, France
| | - A-S Alonso
- Departement of Retina, Centre d'investigation clinique, Paris, France
| | - J Lafolie
- Departement of Retina, Centre d'investigation clinique, Paris, France
| | - V Michaud
- CHU de Bordeaux, Hôpital Pellegrin, Bordeaux, France
| | - E Lasseaux
- CHU de Bordeaux, Hôpital Pellegrin, Bordeaux, France
| | - V Vasseur
- Departement of Retina, Centre d'investigation clinique, Paris, France
| | - S Derrien
- Departement of Retina, Rothschild Foundation hospital, Paris, France.,Departement of Retina, Centre d'investigation clinique, Paris, France
| | - M P Robert
- Department of ophthalmology, Hôpital Necker, APHP, Paris, France
| | - Y Le Mer
- Departement of Retina, Rothschild Foundation hospital, Paris, France
| | - R Tadayoni
- Departement of Retina, Rothschild Foundation hospital, Paris, France
| | - B Arveiler
- CHU de Bordeaux, Hôpital Pellegrin, Bordeaux, France
| | - M Mauget-Faÿsse
- Departement of Retina, Rothschild Foundation hospital, Paris, France.,Departement of Retina, Centre d'investigation clinique, Paris, France
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23
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The retinal pigmentation pathway in human albinism: Not so black and white. Prog Retin Eye Res 2022; 91:101091. [PMID: 35729001 DOI: 10.1016/j.preteyeres.2022.101091] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 05/24/2022] [Accepted: 05/26/2022] [Indexed: 12/16/2022]
Abstract
Albinism is a pigment disorder affecting eye, skin and/or hair. Patients usually have decreased melanin in affected tissues and suffer from severe visual abnormalities, including foveal hypoplasia and chiasmal misrouting. Combining our data with those of the literature, we propose a single functional genetic retinal signalling pathway that includes all 22 currently known human albinism disease genes. We hypothesise that defects affecting the genesis or function of different intra-cellular organelles, including melanosomes, cause syndromic forms of albinism (Hermansky-Pudlak (HPS) and Chediak-Higashi syndrome (CHS)). We put forward that specific melanosome impairments cause different forms of oculocutaneous albinism (OCA1-8). Further, we incorporate GPR143 that has been implicated in ocular albinism (OA1), characterised by a phenotype limited to the eye. Finally, we include the SLC38A8-associated disorder FHONDA that causes an even more restricted "albinism-related" ocular phenotype with foveal hypoplasia and chiasmal misrouting but without pigmentation defects. We propose the following retinal pigmentation pathway, with increasingly specific genetic and cellular defects causing an increasingly specific ocular phenotype: (HPS1-11/CHS: syndromic forms of albinism)-(OCA1-8: OCA)-(GPR143: OA1)-(SLC38A8: FHONDA). Beyond disease genes involvement, we also evaluate a range of (candidate) regulatory and signalling mechanisms affecting the activity of the pathway in retinal development, retinal pigmentation and albinism. We further suggest that the proposed pigmentation pathway is also involved in other retinal disorders, such as age-related macular degeneration. The hypotheses put forward in this report provide a framework for further systematic studies in albinism and melanin pigmentation disorders.
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24
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Malechka VV, Duong D, Bordonada KD, Turriff A, Blain D, Murphy E, Introne WJ, Gochuico BR, Adams DR, Zein WM, Brooks BP, Huryn LA, Solomon BD, Hufnagel RB. Investigating Determinants and Evaluating Deep Learning Training Approaches for Visual Acuity in Foveal Hypoplasia. OPHTHALMOLOGY SCIENCE 2022; 3:100225. [PMID: 36339947 PMCID: PMC9634033 DOI: 10.1016/j.xops.2022.100225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 08/30/2022] [Accepted: 09/19/2022] [Indexed: 11/13/2022]
Abstract
Purpose To describe the relationships between foveal structure and visual function in a cohort of individuals with foveal hypoplasia (FH) and to estimate FH grade and visual acuity using a deep learning classifier. Design Retrospective cohort study and experimental study. Participants A total of 201 patients with FH were evaluated at the National Eye Institute from 2004 to 2018. Methods Structural components of foveal OCT scans and corresponding clinical data were analyzed to assess their contributions to visual acuity. To automate FH scoring and visual acuity correlations, we evaluated the following 3 inputs for training a neural network predictor: (1) OCT scans, (2) OCT scans and metadata, and (3) real OCT scans and fake OCT scans created from a generative adversarial network. Main Outcome Measures The relationships between visual acuity outcomes and determinants, such as foveal morphology, nystagmus, and refractive error. Results The mean subject age was 24.4 years (range, 1–73 years; standard deviation = 18.25 years) at the time of OCT imaging. The mean best-corrected visual acuity (n = 398 eyes) was equivalent to a logarithm of the minimal angle of resolution (LogMAR) value of 0.75 (Snellen 20/115). Spherical equivalent refractive error (SER) ranged from −20.25 diopters (D) to +13.63 D with a median of +0.50 D. The presence of nystagmus and a high-LogMAR value showed a statistically significant relationship (P < 0.0001). The participants whose SER values were farther from plano demonstrated higher LogMAR values (n = 382 eyes). The proportion of patients with nystagmus increased with a higher FH grade. Variability in SER with grade 4 (range, −20.25 D to +13.00 D) compared with grade 1 (range, −8.88 D to +8.50 D) was statistically significant (P < 0.0001). Our neural network predictors reliably estimated the FH grading and visual acuity (correlation to true value > 0.85 and > 0.70, respectively) for a test cohort of 37 individuals (98 OCT scans). Training the predictor on real OCT scans with metadata and fake OCT scans improved the accuracy over the model trained on real OCT scans alone. Conclusions Nystagmus and foveal anatomy impact visual outcomes in patients with FH, and computational algorithms reliably estimate FH grading and visual acuity.
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25
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Al-Nosairy KO, Quanz EV, Biermann J, Hoffmann MB. Optical Coherence Tomography as a Biomarker for Differential Diagnostics in Nystagmus: Ganglion Cell Layer Thickness Ratio. J Clin Med 2022; 11:jcm11174941. [PMID: 36078871 PMCID: PMC9456294 DOI: 10.3390/jcm11174941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 08/12/2022] [Accepted: 08/13/2022] [Indexed: 11/25/2022] Open
Abstract
In albinism, with the use of optical coherence tomography (OCT), a thinning of the macular ganglion cell layer was recently reported. As a consequence, the relevant OCT measure, i.e., a reduction of the temporal/nasal ganglion cell layer thickness quotient (GCLTQ), is a strong candidate for a novel biomarker of albinism. However, nystagmus is a common trait in albinism and is known as a potential confound of imaging techniques. Therefore, there is a need to determine the impact of nystagmus without albinism on the GCLTQ. In this bi-center study, the retinal GCLTQ was determined (OCT Spectralis, Heidelberg Engineering, Heidelberg, Germany) for healthy controls (n = 5, 10 eyes) vs. participants with nystagmus and albinism (Nalbinism, n = 8, 15 eyes), and with nystagmus of other origins (Nother, n = 11, 17 eyes). Macular OCT with 25 horizontal B scans 20 × 20° with 9 automated real time tracking (ART) frames centered on the retina was obtained for each group. From the sectoral GCLTs of the early treatment diabetic retinopathy study (ETDRS) circular thickness maps, i.e., 3 mm and 6 mm ETDRS rings, GCLTQ I and GCLTQ II were determined. Both GCLTQs were reduced in Nalbinism (GCLTQ I and II: 0.78 and 0.77, p < 0.001) compared to Nother (0.91 and 0.93) and healthy controls (0.89 and 0.95). The discrimination of Nalbinism from Nother via GCLTQ I and II had an area under the curve of 80 and 82% with an optimal cutoff point of 0.86 and 0.88, respectively. In conclusion, lower GCLTQ in Nalbinism appears as a distinguished feature in albinism-related nystagmus as opposed to other causes of nystagmus.
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Affiliation(s)
- Khaldoon O. Al-Nosairy
- Department of Ophthalmology, Faculty of Medicine, Otto-von-Guericke University, 39120 Magdeburg, Germany
| | - Elisabeth V. Quanz
- Department of Ophthalmology, Faculty of Medicine, Otto-von-Guericke University, 39120 Magdeburg, Germany
| | - Julia Biermann
- Department of Ophthalmology, University of Muenster Medical Centre, 48149 Muenster, Germany
| | - Michael B. Hoffmann
- Department of Ophthalmology, Faculty of Medicine, Otto-von-Guericke University, 39120 Magdeburg, Germany
- Center for Behavioral Brain Sciences, 39118 Magdeburg, Germany
- Correspondence:
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26
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Hansen TB, Torner-Jordana J, Kessel L. Photosensitivity and filter efficacy in albinism ✰. JOURNAL OF OPTOMETRY 2022:S1888-4296(22)00042-5. [PMID: 36028395 DOI: 10.1016/j.optom.2022.07.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 06/29/2022] [Accepted: 07/03/2022] [Indexed: 06/15/2023]
Abstract
PURPOSE To describe the prevalence and severity of photosensitivity in patients with albinism, and to compare with ocular features and how this correlated with use and choice of optical filters. METHODS Cross-sectional study on 81 participants with ocular or oculocutaneous albinism. An ophthalmic evaluation including visual acuity, contrast sensitivity and evaluation of iris translucency and fundus hypopigmentation was performed. Participants were offered optical rehabilitation with testing of a wide panel of filters. The associations between ocular characteristics, subjective photosensitivity complaints, and filter choice were evaluated. RESULTS Photosensitivity was rated as "some" to "worst imaginable" in 77.8% of participants. Severity of photosensitivity correlated significantly with fundus hypopigmentation (p = 0.04) but not with iris translucency (p = 0.14) and it was worse in those with poor visual acuity but there was no association between photosensitivity and contrast vision. Seventy-four new pairs of spectacles were prescribed in the study. All outdoor spectacles contained a filter, whereas 26.5% of new indoor spectacles did not. Relatively neutral filter colors (gray, brown or a combination of gray and brown with other colors) and low transmission were preferred. DISCUSSION Photosensitivity is common in albinism, but research targeting treatment is limited. Color and neutral filters with a low light transmission were preferred, with participants having a large number of spectacles, presumably to meet their needs in different situations.
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Affiliation(s)
- Tanja B Hansen
- Department of Ophthalmology. Copenhagen University Hospital - Rigshospitalet. Denmark
| | | | - Line Kessel
- Department of Ophthalmology. Copenhagen University Hospital - Rigshospitalet. Denmark; Department of Clinical Medicine. University of Copenhagen. Denmark; Department of Clinical Medicine. University of Aarhus. Denmark.
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27
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Chen C, Wang R, Yuan Y, Li J, Yu X. Clinical Features and Novel Genetic Variants Associated with Hermansky-Pudlak Syndrome. Genes (Basel) 2022; 13:genes13071283. [PMID: 35886065 PMCID: PMC9321923 DOI: 10.3390/genes13071283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 07/05/2022] [Accepted: 07/14/2022] [Indexed: 11/16/2022] Open
Abstract
Hermansky-Pudlak syndrome (HPS) is a rare autosomal recessive syndromic form of albinism, characterized by oculocutaneous albinism (OCA) and other systemic complications. The purpose of this study was to investigate patients with HPS-associated gene mutations and describe associated ocular and extraocular phenotypes. Fifty-four probands clinically diagnosed as albinism were enrolled. Ophthalmic examinations and genetic testing were performed in all subjects. The phenotypic and genetic features were evaluated. HPS-associated gene mutation was identified in four of the patients with albinism phenotype. Clinically, photophobia, and nystagmus was detected in all (4/4) patients, and strabismus was found in one (1/4) patient. Fundus examination revealed fundus hypopigmentation and foveal hypoplasia in all (8/8) eyes. Eight novel causative mutations were detected in these four HPS probands. Five (62.5%, 5/8) of the mutations were nonsense, two of the mutations were missense (25%, 2/8), and one of the mutations was frameshift (12.5%, 1/8). All patients in our study carried compound heterozygous variants, and all these pathogenic variants were identified to be novel, with most (62.5%, 5/8) of the mutations being nonsense. Our results improved the understanding of clinical ocular features, and expanded the spectrum of known variants and the genetic background of HPS.
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28
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Expanding the Spectrum of Oculocutaneous Albinism: Does Isolated Foveal Hypoplasia Really Exist? Int J Mol Sci 2022; 23:ijms23147825. [PMID: 35887175 PMCID: PMC9317384 DOI: 10.3390/ijms23147825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2022] [Revised: 07/12/2022] [Accepted: 07/13/2022] [Indexed: 02/05/2023] Open
Abstract
Oculocutaneous albinism is an autosomal recessive disorder characterized by the presence of typical ocular features, such as foveal hypoplasia, iris translucency, hypopigmented fundus oculi and reduced pigmentation of skin and hair. Albino patients can show significant clinical variability; some individuals can present with only mild depigmentation and subtle ocular changes. Here, we provide a retrospective review of the standardized clinical charts of patients firstly addressed for evaluation of foveal hypoplasia and slightly subnormal visual acuity, whose diagnosis of albinism was achieved only after extensive phenotypic and genotypic characterization. Our report corroborates the pathogenicity of the two common TYR polymorphisms p.(Arg402Gln) and p.(Ser192Tyr) when both are located in trans with a pathogenic TYR variant and aims to expand the phenotypic spectrum of albinism in order to increase the detection rate of the albino phenotype. Our data also suggest that isolated foveal hypoplasia should be considered a clinical sign instead of a definitive diagnosis of an isolated clinical entity, and we recommend deep phenotypic and molecular characterization in such patients to achieve a proper diagnosis.
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29
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Michaud V, Lasseaux E, Green DJ, Gerrard DT, Plaisant C, Fitzgerald T, Birney E, Arveiler B, Black GC, Sergouniotis PI. The contribution of common regulatory and protein-coding TYR variants to the genetic architecture of albinism. Nat Commun 2022; 13:3939. [PMID: 35803923 PMCID: PMC9270319 DOI: 10.1038/s41467-022-31392-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 06/15/2022] [Indexed: 12/13/2022] Open
Abstract
Genetic diseases have been historically segregated into rare Mendelian disorders and common complex conditions. Large-scale studies using genome sequencing are eroding this distinction and are gradually unmasking the underlying complexity of human traits. Here, we analysed data from the Genomics England 100,000 Genomes Project and from a cohort of 1313 individuals with albinism aiming to gain insights into the genetic architecture of this archetypal rare disorder. We investigated the contribution of protein-coding and regulatory variants both rare and common. We focused on TYR, the gene encoding tyrosinase, and found that a high-frequency promoter variant, TYR c.-301C>T [rs4547091], modulates the penetrance of a prevalent, albinism-associated missense change, TYR c.1205G>A (p.Arg402Gln) [rs1126809]. We also found that homozygosity for a haplotype formed by three common, functionally-relevant variants, TYR c.[-301C;575C>A;1205G>A], is associated with a high probability of receiving an albinism diagnosis (OR>82). This genotype is also associated with reduced visual acuity and with increased central retinal thickness in UK Biobank participants. Finally, we report how the combined analysis of rare and common variants can increase diagnostic yield and can help inform genetic counselling in families with albinism.
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Affiliation(s)
- Vincent Michaud
- Department of Medical Genetics, University Hospital of Bordeaux, Bordeaux, France
- INSERM U1211, Rare Diseases, Genetics and Metabolism, University of Bordeaux, Bordeaux, France
| | - Eulalie Lasseaux
- Department of Medical Genetics, University Hospital of Bordeaux, Bordeaux, France
| | - David J Green
- Division of Evolution, Infection and Genomics, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Dave T Gerrard
- Division of Evolution, Infection and Genomics, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Claudio Plaisant
- Department of Medical Genetics, University Hospital of Bordeaux, Bordeaux, France
| | - Tomas Fitzgerald
- European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL- EBI), Wellcome Genome Campus, Cambridge, UK
| | - Ewan Birney
- European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL- EBI), Wellcome Genome Campus, Cambridge, UK
| | - Benoît Arveiler
- Department of Medical Genetics, University Hospital of Bordeaux, Bordeaux, France.
- INSERM U1211, Rare Diseases, Genetics and Metabolism, University of Bordeaux, Bordeaux, France.
| | - Graeme C Black
- Division of Evolution, Infection and Genomics, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK.
- Manchester Centre for Genomic Medicine, Saint Mary's Hospital, Manchester University NHS Foundation Trust, Manchester, UK.
| | - Panagiotis I Sergouniotis
- Division of Evolution, Infection and Genomics, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK.
- European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL- EBI), Wellcome Genome Campus, Cambridge, UK.
- Manchester Centre for Genomic Medicine, Saint Mary's Hospital, Manchester University NHS Foundation Trust, Manchester, UK.
- Manchester Royal Eye Hospital, Manchester University NHS Foundation Trust, Manchester, UK.
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30
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Bhate M, Lalwani S, Chakrabarti S. Phenotypic variations in ocular features among siblings with oculocutaneous albinism. Indian J Ophthalmol 2022; 70:2511-2515. [PMID: 35791147 PMCID: PMC9426174 DOI: 10.4103/ijo.ijo_1025_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Purpose: To assess the clinical profiles, presenting ocular features, and variations in the phenotypic features in siblings with oculocutaneous albinism (OCA). Methods: Electronic medical records of consecutive siblings diagnosed with albinism from January 2016 to December 2020 were reviewed to identify the affected siblings. The variations in their phenotypic characteristics were studied. Results: Significant variations were observed in the clinical features between the siblings (n = 42). A difference of >2 lines in visual acuity was observed in 50% (n = 21) of the sibling pairs. Compound hyperopic astigmatism was the commonest refractive error. The refractive status was different in 80.95% (n = 34) pairs. Although individually strabismus and abnormal head posture were observed in one-third and one-fourth of individual children, respectively, both siblings with similar strabismus were seen in only 16.67% (n = 7) and with a similar abnormal head posture in 13.33% (n = 5). Nystagmus was the most consistent finding across these siblings with a similar nature of horizontal jerk or pendular in 65% of sibling pairs. Conclusion: This study observed significant variations in phenotypic presentations among siblings with OCA. Such differences in clinical manifestations and severity would be helpful in appropriate counseling of these families as the need for rehabilitation services is likely to vary across siblings.
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Affiliation(s)
- Manjushree Bhate
- Strabismus, Pediatric and Neuro-Ophthalmology, Jasti V. Ramanamma Children's Eye Care Centre, L.V. Prasad Eye Institute, Hyderabad, Telangana, India
| | - Sakshi Lalwani
- Strabismus, Pediatric and Neuro-Ophthalmology, Jasti V. Ramanamma Children's Eye Care Centre, L.V. Prasad Eye Institute, Hyderabad, Telangana, India
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Tingaud-Sequeira A, Mercier E, Michaud V, Pinson B, Gazova I, Gontier E, Decoeur F, McKie L, Jackson IJ, Arveiler B, Javerzat S. The Dct−/− Mouse Model to Unravel Retinogenesis Misregulation in Patients with Albinism. Genes (Basel) 2022; 13:genes13071164. [PMID: 35885947 PMCID: PMC9324463 DOI: 10.3390/genes13071164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 06/21/2022] [Accepted: 06/24/2022] [Indexed: 11/16/2022] Open
Abstract
We have recently identified DCT encoding dopachrome tautomerase (DCT) as the eighth gene for oculocutaneous albinism (OCA). Patients with loss of function of DCT suffer from eye hypopigmentation and retinal dystrophy. Here we investigate the eye phenotype in Dct−/− mice. We show that their retinal pigmented epithelium (RPE) is severely hypopigmented from early stages, contrasting with the darker melanocytic tissues. Multimodal imaging reveals specific RPE cellular defects. Melanosomes are fewer with correct subcellular localization but disrupted melanization. RPE cell size is globally increased and heterogeneous. P-cadherin labeling of Dct−/− newborn RPE reveals a defect in adherens junctions similar to what has been described in tyrosinase-deficient Tyrc/c embryos. The first intermediate of melanin biosynthesis, dihydroxyphenylalanine (L-Dopa), which is thought to control retinogenesis, is detected in substantial yet significantly reduced amounts in Dct−/− postnatal mouse eyecups. L-Dopa synthesis in the RPE alone remains to be evaluated during the critical period of retinogenesis. The Dct−/− mouse should prove useful in understanding the molecular regulation of retinal development and aging of the hypopigmented eye. This may guide therapeutic strategies to prevent vision deficits in patients with albinism.
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Affiliation(s)
- Angèle Tingaud-Sequeira
- Rare Diseases Genetics and Metabolism, INSERM U1211, SBM Department, University of Bordeaux, F-33076 Bordeaux, France; (A.T.-S.); (E.M.); (V.M.); (B.A.)
| | - Elina Mercier
- Rare Diseases Genetics and Metabolism, INSERM U1211, SBM Department, University of Bordeaux, F-33076 Bordeaux, France; (A.T.-S.); (E.M.); (V.M.); (B.A.)
| | - Vincent Michaud
- Rare Diseases Genetics and Metabolism, INSERM U1211, SBM Department, University of Bordeaux, F-33076 Bordeaux, France; (A.T.-S.); (E.M.); (V.M.); (B.A.)
- Molecular Genetics Laboratory, Bordeaux University Hospital, F-33076 Bordeaux, France
| | - Benoît Pinson
- SAM, TBMcore, CNRS UAR 3427, INSERM US005, Université Bordeaux, F-33076 Bordeaux, France;
| | - Ivet Gazova
- MRC Human Genetics Unit, University of Edinburgh, Edinburgh EH4 2XU, UK; (I.G.); (L.M.); (I.J.J.)
| | - Etienne Gontier
- Bordeaux Imaging Center, CNRS, INSERM, BIC, UMS 3420, US 4, University Bordeaux, F-33076 Bordeaux, France; (E.G.); (F.D.)
| | - Fanny Decoeur
- Bordeaux Imaging Center, CNRS, INSERM, BIC, UMS 3420, US 4, University Bordeaux, F-33076 Bordeaux, France; (E.G.); (F.D.)
| | - Lisa McKie
- MRC Human Genetics Unit, University of Edinburgh, Edinburgh EH4 2XU, UK; (I.G.); (L.M.); (I.J.J.)
| | - Ian J. Jackson
- MRC Human Genetics Unit, University of Edinburgh, Edinburgh EH4 2XU, UK; (I.G.); (L.M.); (I.J.J.)
| | - Benoît Arveiler
- Rare Diseases Genetics and Metabolism, INSERM U1211, SBM Department, University of Bordeaux, F-33076 Bordeaux, France; (A.T.-S.); (E.M.); (V.M.); (B.A.)
- Molecular Genetics Laboratory, Bordeaux University Hospital, F-33076 Bordeaux, France
| | - Sophie Javerzat
- Rare Diseases Genetics and Metabolism, INSERM U1211, SBM Department, University of Bordeaux, F-33076 Bordeaux, France; (A.T.-S.); (E.M.); (V.M.); (B.A.)
- Correspondence:
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Zamani Varkaneh M, Khodabakhshi-Koolaee A, Sheikhi MR. Identifying psychosocial challenges and introducing coping strategies for people with albinism. BRITISH JOURNAL OF VISUAL IMPAIRMENT 2022. [DOI: 10.1177/02646196221099155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Albinism refers to a group of genetic disorders that, following genetic mutations, lead to impaired melanin production, resulting in skin allergies and visual impairment in affected people. Visual impairment brings not only physical limitations and challenges but also many social problems, including psychosocial challenges, leading to different experiences in the lives of these people. To this end, using a qualitative content analysis approach, the present study aimed to identify psychosocial challenges and introduce coping strategies for people with albinism living in Tehran in 2021. The participants were people with albinism aged 20 to 40 years in Tehran. The participants were selected from among members of the Iranian Albinism Association (AMAL) using purposive sampling. The data were saturated through semi-structured interviews with 20 participants in the research sample. The collected data were analyzed using conventional content analysis. Analysis of the participants’ experiences revealed three main themes: (1) The challenges and difficulties of living with albinism, (2) welfare, specialized facilities, and support seeking, and (3) strategies for coping with psychosocial challenges. According to the findings, albinism, due to its limitations, brings many bitter and painful experiences in education, job finding, and marriage for affected patients. The condition is also associated with some limitations such as visual impairment affecting various aspects of the patient’s life and different developmental periods. Each person may have different interpretations of their challenges and thus seek unique strategies for coping with the challenges. The findings of this study can have some implications for mental health professionals and managers of relevant institutions and to become aware of the nature and complications of albinism, the challenges faced by people with albinism, and the special needs of these people. Findings from this study can be used to identify the relationship between albinism, the challenges of living with albinism, and the special needs of these individuals, by mental health professionals, related institutions, and psychosocial environments.
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Affiliation(s)
| | | | - Mohammad Reza Sheikhi
- Social Determinants of Health Research Center, Research Institute for Prevention of Non-Communicable Diseases, Qazvin University of Medical Sciences, Qazvin, Iran
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Kuht HJ, Maconachie GDE, Han J, Kessel L, van Genderen MM, McLean RJ, Hisaund M, Tu Z, Hertle RW, Gronskov K, Bai D, Wei A, Li W, Jiao Y, Smirnov V, Choi JH, Tobin MD, Sheth V, Purohit R, Dawar B, Girach A, Strul S, May L, Chen FK, Heath Jeffery RC, Aamir A, Sano R, Jin J, Brooks BP, Kohl S, Arveiler B, Montoliu L, Engle EC, Proudlock FA, Nishad G, Pani P, Varma G, Gottlob I, Thomas MG. Genotypic and Phenotypic Spectrum of Foveal Hypoplasia: A Multicenter Study. Ophthalmology 2022; 129:708-718. [PMID: 35157951 PMCID: PMC9341240 DOI: 10.1016/j.ophtha.2022.02.010] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 02/03/2022] [Accepted: 02/07/2022] [Indexed: 01/01/2023] Open
Abstract
PURPOSE To characterize the genotypic and phenotypic spectrum of foveal hypoplasia (FH). DESIGN Multicenter, observational study. PARTICIPANTS A total of 907 patients with a confirmed molecular diagnosis of albinism, PAX6, SLC38A8, FRMD7, AHR, or achromatopsia from 12 centers in 9 countries (n = 523) or extracted from publicly available datasets from previously reported literature (n = 384). METHODS Individuals with a confirmed molecular diagnosis and availability of foveal OCT scans were identified from 12 centers or from the literature between January 2011 and March 2021. A genetic diagnosis was confirmed by sequence analysis. Grading of FH was derived from OCT scans. MAIN OUTCOME MEASURES Grade of FH, presence or absence of photoreceptor specialization (PRS+ vs. PRS-), molecular diagnosis, and visual acuity (VA). RESULTS The most common genetic etiology for typical FH in our cohort was albinism (67.5%), followed by PAX6 (21.8%), SLC38A8 (6.8%), and FRMD7 (3.5%) variants. AHR variants were rare (0.4%). Atypical FH was seen in 67.4% of achromatopsia cases. Atypical FH in achromatopsia had significantly worse VA than typical FH (P < 0.0001). There was a significant difference in the spectrum of FH grades based on the molecular diagnosis (chi-square = 60.4, P < 0.0001). All SLC38A8 cases were PRS- (P = 0.003), whereas all FRMD7 cases were PRS+ (P < 0.0001). Analysis of albinism subtypes revealed a significant difference in the grade of FH (chi-square = 31.4, P < 0.0001) and VA (P = 0.0003) between oculocutaneous albinism (OCA) compared with ocular albinism (OA) and Hermansky-Pudlak syndrome (HPS). Ocular albinism and HPS demonstrated higher grades of FH and worse VA than OCA. There was a significant difference (P < 0.0001) in VA between FRMD7 variants compared with other diagnoses associated with FH. CONCLUSIONS We characterized the phenotypic and genotypic spectrum of FH. Atypical FH is associated with a worse prognosis than all other forms of FH. In typical FH, our data suggest that arrested retinal development occurs earlier in SLC38A8, OA, HPS, and AHR variants and later in FRMD7 variants. The defined time period of foveal developmental arrest for OCA and PAX6 variants seems to demonstrate more variability. Our findings provide mechanistic insight into disorders associated with FH and have significant prognostic and diagnostic value.
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Affiliation(s)
- Helen J Kuht
- The University of Leicester Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University of Leicester, Leicester, United Kingdom; Foveal Development Investigators Group
| | - Gail D E Maconachie
- The University of Leicester Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University of Leicester, Leicester, United Kingdom; Academic Unit of Ophthalmology and Orthoptics, University of Sheffield, Sheffield, United Kingdom; Foveal Development Investigators Group
| | - Jinu Han
- Institute of Vision Research, Department of Ophthalmology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea; Foveal Development Investigators Group
| | - Line Kessel
- Department of Ophthalmology, Rigshospitalet, Denmark; Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark; Foveal Development Investigators Group
| | - Maria M van Genderen
- Department of Ophthalmology, University Medical Centre Utrecht, Utrecht, The Netherlands; Bartiméus Diagnostic Centre for Complex Visual Disorders, Zeist, The Netherlands; Foveal Development Investigators Group
| | - Rebecca J McLean
- The University of Leicester Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University of Leicester, Leicester, United Kingdom
| | - Michael Hisaund
- The University of Leicester Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University of Leicester, Leicester, United Kingdom
| | - Zhanhan Tu
- The University of Leicester Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University of Leicester, Leicester, United Kingdom; Foveal Development Investigators Group
| | - Richard W Hertle
- Department of Ophthalmology, The Rebecca D. Considine Research Institute and The Children's Vision Center, Akron Children's Hospital, Akron, Ohio; Department of Surgery, The Northeastern Ohio Medical University, Rootstown, Ohio; Foveal Development Investigators Group
| | - Karen Gronskov
- Department of Clinical Genetics, Rigshospitalet-Kennedy Center, Glostrup, Denmark; Foveal Development Investigators Group
| | - Dayong Bai
- Department of Ophthalmology, Beijing Children's Hospital, National Center for Children's Health, Capital Medical University, Beijing, China; Foveal Development Investigators Group
| | - Aihua Wei
- Department of Dermatology, Beijing Tongren Hospital, Capital Medical University, Beijing, China; Foveal Development Investigators Group
| | - Wei Li
- Beijing Key Laboratory for Genetics of Birth Defects, Beijing Pediatric Research Institute; Rare Disease Center, National Center for Children's Health; MOE Key Laboratory of Major Diseases in Children, Beijing Children's Hospital, Capital Medical University, Beijing, China; Foveal Development Investigators Group
| | - Yonghong Jiao
- Beijing Tongren Eye Centre, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology and Visual Science Key Lab, Beijing, China; Foveal Development Investigators Group
| | - Vasily Smirnov
- Sorbonne Université, Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche Scientifique, Institut de la Vision, Paris, France; Exploration de la Vision et Neuro-Ophtalmologie, CHU de Lille, Lille, France; Foveal Development Investigators Group
| | - Jae-Hwan Choi
- Department of Neurology, Pusan National University School of Medicine, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, South Korea; Foveal Development Investigators Group
| | - Martin D Tobin
- Department of Health Sciences, University of Leicester, Leicester, United Kingdom; Foveal Development Investigators Group
| | - Viral Sheth
- The University of Leicester Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University of Leicester, Leicester, United Kingdom; Academic Unit of Ophthalmology and Orthoptics, University of Sheffield, Sheffield, United Kingdom
| | - Ravi Purohit
- The University of Leicester Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University of Leicester, Leicester, United Kingdom
| | - Basu Dawar
- The University of Leicester Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University of Leicester, Leicester, United Kingdom
| | - Ayesha Girach
- The University of Leicester Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University of Leicester, Leicester, United Kingdom
| | - Sasha Strul
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, Minnesota; Foveal Development Investigators Group
| | - Laura May
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, Minnesota; Foveal Development Investigators Group
| | - Fred K Chen
- Centre for Ophthalmology and Visual Science (incorporating Lions Eye Institute), The University of Western Australia, Crawley, Australia; Foveal Development Investigators Group
| | - Rachael C Heath Jeffery
- Centre for Ophthalmology and Visual Science (incorporating Lions Eye Institute), The University of Western Australia, Crawley, Australia; Foveal Development Investigators Group
| | - Abdullah Aamir
- The University of Leicester Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University of Leicester, Leicester, United Kingdom
| | - Ronaldo Sano
- Retina and Vitreous Sector of Santa Casa de Misericórdia de São Paulo, São Paulo, Brazil; Foveal Development Investigators Group
| | - Jing Jin
- Sidney Kimmel Medical College of Thomas Jefferson University, Nemours Children's Health, Philadelphia, Pennsylvania; Nemours Children's Health, Wilmington, Delaware
| | - Brian P Brooks
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland; Foveal Development Investigators Group
| | - Susanne Kohl
- Centre for Ophthalmology, Institute for Ophthalmic Research, University Tübingen, Tübingen, Germany; Foveal Development Investigators Group
| | - Benoit Arveiler
- Rare Diseases, Genetics and Metabolism, INSERM U1211, University of Bordeaux, Bordeaux, France; Molecular Genetics Laboratory, Bordeaux University Hospital, Bordeaux, France; Foveal Development Investigators Group
| | - Lluis Montoliu
- National Centre for Biotechnology (CNB-CSIC) and CIBERER-ISCIII, Madrid, Spain; Foveal Development Investigators Group
| | - Elizabeth C Engle
- Departments of Neurology and Ophthalmology, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts; Howard Hughes Medical Institute, Chevy Chase, Maryland; Foveal Development Investigators Group
| | - Frank A Proudlock
- The University of Leicester Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University of Leicester, Leicester, United Kingdom
| | - Garima Nishad
- International Institute of Information Technology, Hyderabad, India
| | - Prateek Pani
- International Institute of Information Technology, Hyderabad, India
| | - Girish Varma
- International Institute of Information Technology, Hyderabad, India; Foveal Development Investigators Group
| | - Irene Gottlob
- The University of Leicester Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University of Leicester, Leicester, United Kingdom; Foveal Development Investigators Group; Cooper Neurological Institute, Cooper Medical School of Rowan University, Camden, New Jersey
| | - Mervyn G Thomas
- The University of Leicester Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University of Leicester, Leicester, United Kingdom; Foveal Development Investigators Group.
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Toufeeq S, Gottlob I, Tu Z, Proudlock FA, Pilat A. Abnormal Retinal Vessel Architecture in Albinism and Idiopathic Infantile Nystagmus. Invest Ophthalmol Vis Sci 2022; 63:33. [PMID: 35616929 PMCID: PMC9150830 DOI: 10.1167/iovs.63.5.33] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Infantile nystagmus syndrome (INS) causes altered visual development and can be associated with abnormal retinal structure, to which vascular development of the retina is closely related. Abnormal retinal vasculature has previously been noted in albinism but not idiopathic infantile nystagmus. We compared the number and diameter of retinal vessels in participants with albinism (PWA) and idiopathic infantile nystagmus (PWIIN) with controls. Methods Fundus photography data from 24 PWA, 10 PWIIN, and 34 controls was analyzed using Automated Retinal Image Analyzer (ARIA) software on a field of analysis centered on the optic disc, the annulus of which extended between 4.2 mm and 8.4 mm in diameter. Results Compared with controls, the mean number of arterial branches was reduced by 24% in PWA (15.5 vs. 20.3, P < 0.001), and venous branches were reduced in both PWA (29%; 12.9 vs. 18.2, P < 0.001) and PWIIN (17%; 15.1 vs. 18.2, P = 0.024). PWA demonstrated 7% thinner "primary" (before branching) arteries (mean diameter: 75.39 µm vs. 80.88 µm, P = 0.043), and 13% thicker (after branching) "secondary" veins (66.72 µm vs. 59.01 µm in controls, P = 0.009). Conclusions PWA and PWIIN demonstrated reduced retinal vessel counts and arterial diameters compared with controls. These changes in the superficial retinal vascular network may be secondary to underdevelopment of the neuronal network, which guides vascular development and is also known to be disrupted in INS.
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Affiliation(s)
- Shafak Toufeeq
- Oxford Eye Hospital, Level LG1 John Radcliffe Hospital, Headley Way, Headington, Oxford OX3 9DU, United Kingdom
| | - Irene Gottlob
- Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University Of Leicester, University Road, Leicester, LE1 7RH, United Kingdom
| | - Zhanhan Tu
- Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University Of Leicester, University Road, Leicester, LE1 7RH, United Kingdom
| | - Frank A. Proudlock
- Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University Of Leicester, University Road, Leicester, LE1 7RH, United Kingdom
| | - Anastasia Pilat
- Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University Of Leicester, University Road, Leicester, LE1 7RH, United Kingdom
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Thomas MG, Papageorgiou E, Kuht HJ, Gottlob I. Normal and abnormal foveal development. Br J Ophthalmol 2022; 106:593-599. [PMID: 33148537 DOI: 10.1136/bjophthalmol-2020-316348] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 10/13/2020] [Accepted: 10/17/2020] [Indexed: 01/06/2023]
Abstract
Normal foveal development begins in utero at midgestation with centrifugal displacement of inner retinal layers (IRLs) from the location of the incipient fovea. The outer retinal changes such as increase in cone cell bodies, cone elongation and packing mainly occur after birth and continue until 13 years of age. The maturity of the fovea can be assessed invivo using optical coherence tomography, which in normal development would show a well-developed foveal pit, extrusion of IRLs, thickened outer nuclear layer and long outer segments. Developmental abnormalities of various degrees can result in foveal hypoplasia (FH). This is a characteristic feature for example in albinism, aniridia, prematurity, foveal hypoplasia with optic nerve decussation defects with or without anterior segment dysgenesis without albinism (FHONDA) and optic nerve hypoplasia. In achromatopsia, there is disruption of the outer retinal layers with atypical FH. Similarly, in retinal dystrophies, there is abnormal lamination of the IRLs sometimes with persistent IRLs. Morphology of FH provides clues to diagnoses, and grading correlates to visual acuity. The outer segment thickness is a surrogate marker for cone density and in foveal hypoplasia this correlates strongly with visual acuity. In preverbal children grading FH can help predict future visual acuity.
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Affiliation(s)
- Mervyn G Thomas
- Department of Neuroscience, Psychology and Behaviour, University of Leicester, Leicester, UK
| | - Eleni Papageorgiou
- Department of Ophthalmology, University Hospital of Larissa, Larissa, Greece
| | - Helen J Kuht
- Department of Neuroscience, Psychology and Behaviour, University of Leicester, Leicester, UK
| | - Irene Gottlob
- Department of Neuroscience, Psychology and Behaviour, University of Leicester, Leicester, UK
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Jin J, Hendricks D, Lehman S, Friess A, Salvin J, Reid J, Wang J. Comparison of OCT imaging in children with foveal hypoplasia born full term versus preterm. Graefes Arch Clin Exp Ophthalmol 2022; 260:3075-3085. [PMID: 35445879 DOI: 10.1007/s00417-022-05664-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 03/07/2022] [Accepted: 04/08/2022] [Indexed: 11/29/2022] Open
Abstract
PURPOSE It is unknown if foveal hypoplasia in full-term born children differs in structure and function from that observed in children born preterm. We compared macular structure and visual function in children with history of prematurity and full-term children diagnosed with foveal hypoplasia. METHODS We compared three groups of subjects (3-18 years old): (1) full-term hypoplasia (FH, n = 56, gestational age ≥ 36 weeks); (2) preterm hypoplasia (n = 57, gestational age ≤ 31 weeks, birth weight ≤ 1500 g); (3) control (n = 54), full-term normal. Using spectral-domain optical coherence tomography volume-scan images, macular structure within 3 mm of Early-Treatment-Diabetic-Retinopathy-Study circle was segmented. Total, inner, and outer foveal thickness of right eyes were compared. Foveal hypoplasia was graded according to the Leicester Grading System. RESULTS The mean total foveal thickness in micrometers was 263 ± 19 for the control, 299 ± 30 for the full-term hypoplasia, and 294 ± 28 for the preterm hypoplasia groups (F = 33, p < 0.001). Foveal inner retinal layer thickness differed among groups (p < 0.001), but not in the outer layers (p = 0.10). The full-term hypoplasia group had significantly thicker foveal inner layers (p < 0.05) and greater frequency of higher-grade hypoplasia than the preterm hypoplasia group. LogMAR visual acuity was worse in the full-term hypoplasia group (0.35 ± 0.36) than in the preterm hypoplasia group (0.19 ± 0.27, p < 0.001). CONCLUSION Fovea was thicker in both hypoplasia groups. The full-term hypoplasia group is associated with more severe structure changes and poorer visual function than the preterm hypoplasia group.
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Affiliation(s)
- Jing Jin
- Department of Pediatric Ophthalmology, Nemours Children's Health, P.O. Box 269, Wilmington, DE, 19899, USA.
| | - Dorothy Hendricks
- Department of Pediatric Ophthalmology, Nemours Children's Health, P.O. Box 269, Wilmington, DE, 19899, USA
| | - Sharon Lehman
- Department of Pediatric Ophthalmology, Nemours Children's Health, P.O. Box 269, Wilmington, DE, 19899, USA
| | - Amanda Friess
- Department of Pediatric Ophthalmology, Nemours Children's Health, P.O. Box 269, Wilmington, DE, 19899, USA
| | - Jonathan Salvin
- Department of Pediatric Ophthalmology, Nemours Children's Health, P.O. Box 269, Wilmington, DE, 19899, USA
| | - Julia Reid
- Department of Pediatric Ophthalmology, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Jingyun Wang
- Department of Biological and Vision Sciences, State University of New York College of Optometry, New York, NY, USA
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Bringmann A, Barth T, Ziemssen F. Morphology of foveal hypoplasia: Hyporeflective zones in the Henle fiber layer of eyes with high-grade foveal hypoplasia. PLoS One 2022; 17:e0266968. [PMID: 35417487 PMCID: PMC9007365 DOI: 10.1371/journal.pone.0266968] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 03/30/2022] [Indexed: 11/19/2022] Open
Abstract
Background Foveal hypoplasia is characterized by the persistance of inner retinal layers at the macular center. We evaluated using spectral-domain optical coherence tomography (SD-OCT) morphological parameters of the macular center of eyes with foveal hypoplasia and describe the presence of hyporeflective zones in the Henle fiber layer (HFL) of eyes with high-grade foveal hypoplasia. Methods Eyes with foveal hypoplasia were classified into two groups: high-grade foveal hypoplasia with thick inner retinal layers at the macular center (thickness above 100 μm; 16 eyes of 9 subjects) and low-grade foveal hypoplasia with thinner inner retinal layers at the macular center (thickness below 100 μm; 25 eyes of 13 subjects). As comparison, SD-OCT images of normal control eyes (n = 75) were investigated. Results Eyes with foveal hypoplasia displayed shorter central photoreceptor outer segments (POS), a thinner central myoid zone, and a thicker central HFL compared to control eyes. Eyes with high-grade foveal hypoplasia also displayed a thinner central outer nuclear layer (ONL) compared to eyes with low-grade foveal hypoplasia and control eyes. There was a negative correlation between the thicknesses of the central ONL and HFL in eyes with foveal hypoplasia; however, the total thickness of both ONL and HFL was similar in all eye populations investigated. Visual acuity of subjects with foveal hypoplasia was negatively correlated to the thickness of the central inner retinal layers and positively correlated to the length of central POS. In contrast to central POS, the length of paracentral POS (0.5 and 1.0 mm nasal from the macular center) was not different between the three eye populations investigated. The paracentral ONL was thickest in eyes with high-grade foveal hypoplasia and thinnest in control eyes. Hyporeflective zones in the HFL were observed on SD-OCT images of eyes with high-grade foveal hypoplasia, but not of eyes with low-grade foveal hypoplasia and control eyes. OCT angiography images recorded at the level of the HFL of eyes with high-grade foveal hypoplasia showed concentric rings of different reflectivity around the macular center; such rings were not observed on images of eyes with low-grade foveal hypoplasia and control eyes. Conclusions It is suggested that the hyporeflective zones in the HFL of eyes with high-grade foveal hypoplasia represent cystoid spaces which are surrounded by Henle fiber bundles. Cystoid spaces are likely formed because there are fewer Henle fibers and a thinner central ONL despite an unchanged thickness of both ONL and HFL. Cystoid spaces may cause the concentric rings of different reflectivity around the macular center in the HFL of eyes with high-grade foveal hypoplasia.
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Affiliation(s)
- Andreas Bringmann
- Department of Ophthalmology and Eye Hospital, University of Leipzig, Leipzig, Germany
- * E-mail:
| | - Thomas Barth
- Department of Ophthalmology and Eye Hospital, University of Leipzig, Leipzig, Germany
| | - Focke Ziemssen
- Department of Ophthalmology and Eye Hospital, University of Leipzig, Leipzig, Germany
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Li C, Chen Q, Wu J, Ren J, Zhang M, Wang H, Li J, Tang Y. Identification and characterization of two novel noncoding tyrosinase (TYR) gene variants leading to oculocutaneous albinism type 1. J Biol Chem 2022; 298:101922. [PMID: 35413289 PMCID: PMC9108984 DOI: 10.1016/j.jbc.2022.101922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Revised: 04/01/2022] [Accepted: 04/03/2022] [Indexed: 11/25/2022] Open
Abstract
Oculocutaneous albinism type 1 (OCA1), resulting from pathogenic variants in the tyrosinase (TYR) gene, refers to a group of phenotypically heterogeneous autosomal recessive disorders characterized by a partial or a complete absence of pigment in the skin/hair and is also associated with common developmental eye defects. In this study, we identified two novel compound heterozygous TYR variants from a Chinese hypopigmentary patient by whole-exome sequencing. Specifically, the two variants were c.-89T>G, located at the core of the initiator E-box (Inr E-box) of the TYR promoter, and p.S16Y (c.47C>A), located within the signal sequence. We performed both in silico analysis and experimental validation and verified these mutations as OCA1 variants that caused either impaired or complete loss of function of TYR. Mechanistically, the Inr E-box variant dampened TYR binding to microphthalmia-associated transcription factor, a master transcriptional regulator of the melanocyte development, whereas the S16Y variant contributed to endoplasmic reticulum retention, a common and principal cause of impaired TYR activity. Interestingly, we found that the Inr E-box variant creates novel protospacer adjacent motif sites, recognized by nucleases SpCas9 and SaCas9-KKH, respectively, without compromising the functional TYR coding sequence. We further used allele-specific genomic editing by CRISPR activation to specifically target the variant promoter and successfully activated its downstream gene expression, which could lead to potential therapeutic benefits. In conclusion, this study expands the spectrum of TYR variants, especially those within the promoter and noncoding regions, which can facilitate genetic counseling and clinical diagnosis of OCA1.
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Affiliation(s)
- Chaoyi Li
- Department of Geriatrics, Xiangya Hospital, Central South University, Changsha, China; Aging Research Center, Xiangya Hospital, Central South University, Changsha, China; National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Qian Chen
- Department of Geriatrics, Xiangya Hospital, Central South University, Changsha, China; Aging Research Center, Xiangya Hospital, Central South University, Changsha, China; National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Junjiao Wu
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China; Department of Rheumatology and Immunology, Xiangya Hospital, Central South University, Changsha, China; Provincial Clinical Research Center for Rheumatic and Immunologic Diseases, Xiangya Hospital, Central South University, Changsha, China
| | - Jie Ren
- Department of Geriatrics, Xiangya Hospital, Central South University, Changsha, China; Aging Research Center, Xiangya Hospital, Central South University, Changsha, China; National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Mengfei Zhang
- Department of Geriatrics, Xiangya Hospital, Central South University, Changsha, China; Aging Research Center, Xiangya Hospital, Central South University, Changsha, China; National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Huakun Wang
- Department of Geriatrics, Xiangya Hospital, Central South University, Changsha, China; Aging Research Center, Xiangya Hospital, Central South University, Changsha, China; National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Jinchen Li
- Department of Geriatrics, Xiangya Hospital, Central South University, Changsha, China; Aging Research Center, Xiangya Hospital, Central South University, Changsha, China; National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Yu Tang
- Department of Geriatrics, Xiangya Hospital, Central South University, Changsha, China; Aging Research Center, Xiangya Hospital, Central South University, Changsha, China; National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China; The Biobank of Xiangya Hospital, Central South University, Changsha, China.
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39
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Sobolev NP, Teplovodskaya VV, Sudakova EP. [Method of surgical treatment of patients with oculocutaneous albinism using artificial iris]. Vestn Oftalmol 2022; 138:58-63. [PMID: 35234422 DOI: 10.17116/oftalma202213801158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Oculocutaneous albinism is a group of autosomal recessive disorders that directly affect the hypopigmentation of the skin, hair, and eyes. According to the World Health Organization, albinism occurs in 1 out of 20 000 people in Europe and North America. Congenital changes in the organ of vision in albinism lead to a significant decrease in the visual functions of patients, worsening their quality of life. PURPOSE To study the results of surgical treatment with implantation of an artificial iris as a diaphragm element in patients with albinism. MATERIAL AND METHODS This article was based on the examination and treatment of 2 patients suffering from oculocutaneous albinism, which is characterized by hypopigmentation of the iris and retinal pigment epithelium of the retina, foveolar hypoplasia, low visual acuity, nystagmus, strabismus and excruciating photophobia. The patients were implanted an artificial iris in both eyes with fixation in the capsular bag in the first patient, and in the ciliary sulcus in the second. RESULTS In both patients, complaints of photophobia and optical phenomena have ceased. Visual acuity increased to 0.2 and remained without regression throughout the entire period of observation. Intraocular pressure and hydrodynamic parameters also remained stable throughout the observation period. The artificial irises were observed by ultrabiomicroscopy to remain in a stable position both when it was implanted in the capsule bag, and when it was seamlessly fixed in the ciliary sulcus. CONCLUSION The surgical interventions relieved patients from glare, at the same time improving visual acuity without correction, as well as achieving a pronounced cosmetic effect and visual rehabilitation. Artificial irises have proven to be a safe and effective way to treat patients with oculocutaneous albinism.
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Affiliation(s)
- N P Sobolev
- S.N. Fedorov National Medical Research Center «MNTK «Eye Microsurgery», Moscow, Russia
| | - V V Teplovodskaya
- S.N. Fedorov National Medical Research Center «MNTK «Eye Microsurgery», Moscow, Russia
| | - E P Sudakova
- S.N. Fedorov National Medical Research Center «MNTK «Eye Microsurgery», Moscow, Russia
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40
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Galli J, Loi E, Morandi A, Scaglioni V, Rossi A, Molinaro A, Pasini N, Semeraro F, Ruberto G, Fazzi E. Neurodevelopmental Profile in Children Affected by Ocular Albinism. Neuropediatrics 2022; 53:7-14. [PMID: 34327695 DOI: 10.1055/s-0041-1732430] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
AIM The aim of this study was to detail the neurodevelopmental profile of subjects affected by ocular albinism (OA) and to collect data on GPR143 gene analysis. DESIGN The design of the study involves a retrospective longitudinal observational case series. METHODS We collected data on the neurodevelopmental profile of 13 children affected by OA from clinical annual assessments conducted for a period of 6 years after the first evaluation. We described visual profile, neuromotor development and neurological examination, cognitive profile, communication and language skills and behavioral characteristics. The GPR143 gene analysis was performed as well. RESULTS Children presented a variable combination of ocular and oculomotor disorders unchanged during the follow-up, a deficit in visual acuity and in contrast sensitivity that progressively improved. Abnormalities in pattern visual evoked potential were found. No deficits were detected at neurological examination and neuromotor development except for a mild impairment in hand-eye coordination observed in five cases. A language delay was observed in five cases, two of whom had also a developmental quotient delay at 2 years evolving to a borderline/deficit cognitive level at preschool age, difficulties in adaptive behavior and autistic-like features were found. Mutations in the GPR143 gene were identified in the two patients who presented the most severe clinical phenotype. CONCLUSION Children with OA may share, in addition to a variable combination of ocular signs and symptoms, a neurodevelopment impairment regarding mostly the cognitive, communicative, and social area, especially those with GPR143 mutation.
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Affiliation(s)
- Jessica Galli
- Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy.,Unit of Child Neurology and Psychiatry, ASST Spedali Civili of Brescia, Brescia, Italy
| | - Erika Loi
- Unit of Child Neurology and Psychiatry, ASST Spedali Civili of Brescia, Brescia, Italy.,Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Alessandra Morandi
- Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy.,Unit of Child Neurology and Psychiatry, ASST Spedali Civili of Brescia, Brescia, Italy
| | - Vera Scaglioni
- Unit of Child Neurology and Psychiatry, ASST Spedali Civili of Brescia, Brescia, Italy
| | - Andrea Rossi
- Unit of Child Neurology and Psychiatry, ASST Spedali Civili of Brescia, Brescia, Italy
| | - Anna Molinaro
- Unit of Child Neurology and Psychiatry, ASST Spedali Civili of Brescia, Brescia, Italy
| | - Nadia Pasini
- Department of Neurological and Vision Sciences, ASST Spedali Civili of Brescia, Eye Clinic, Brescia, Italy
| | - Francesco Semeraro
- Department of Neurological and Vision Sciences, ASST Spedali Civili of Brescia and University of Brescia, Eye Clinic, Brescia, Italy
| | - Giulio Ruberto
- Department of Surgical and Clinical, Diagnostic and Pediatric Sciences, Section of Ophthalmology, Univeristy of Pavia, IRCCS Fondazione Policlinico San Matteo, Pavia, Italy
| | - Elisa Fazzi
- Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy.,Unit of Child Neurology and Psychiatry, ASST Spedali Civili of Brescia, Brescia, Italy
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41
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Lin S, Sanchez-Bretaño A, Leslie JS, Williams KB, Lee H, Thomas NS, Callaway J, Deline J, Ratnayaka JA, Baralle D, Schmitt MA, Norman CS, Hammond S, Harlalka GV, Ennis S, Cross HE, Wenger O, Crosby AH, Baple EL, Self JE. Evidence that the Ser192Tyr/Arg402Gln in cis Tyrosinase gene haplotype is a disease-causing allele in oculocutaneous albinism type 1B (OCA1B). NPJ Genom Med 2022; 7:2. [PMID: 35027574 PMCID: PMC8758782 DOI: 10.1038/s41525-021-00275-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 11/19/2021] [Indexed: 01/09/2023] Open
Abstract
Oculocutaneous albinism type 1 (OCA1) is caused by pathogenic variants in the TYR (tyrosinase) gene which encodes the critical and rate-limiting enzyme in melanin synthesis. It is the most common OCA subtype found in Caucasians, accounting for ~50% of cases worldwide. The apparent 'missing heritability' in OCA is well described, with ~25-30% of clinically diagnosed individuals lacking two clearly pathogenic variants. Here we undertook empowered genetic studies in an extensive multigenerational Amish family, alongside a review of previously published literature, a retrospective analysis of in-house datasets, and tyrosinase activity studies. Together this provides irrefutable evidence of the pathogenicity of two common TYR variants, p.(Ser192Tyr) and p.(Arg402Gln) when inherited in cis alongside a pathogenic TYR variant in trans. We also show that homozygosity for the p.(Ser192Tyr)/p.(Arg402Gln) TYR haplotype results in a very mild, but fully penetrant, albinism phenotype. Together these data underscore the importance of including the TYR p.(Ser192Tyr)/p.(Arg402Gln) in cis haplotype as a pathogenic allele causative of OCA, which would likely increase molecular diagnoses in this missing heritability albinism cohort by 25-50%.
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Affiliation(s)
- Siying Lin
- RILD Wellcome Wolfson Centre, Royal Devon & Exeter NHS Foundation Trust, Barrack Road, Exeter, UK
| | - Aida Sanchez-Bretaño
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Joseph S Leslie
- RILD Wellcome Wolfson Centre, Royal Devon & Exeter NHS Foundation Trust, Barrack Road, Exeter, UK
| | - Katie B Williams
- Center for Special Children, Vernon Memorial Healthcare, La Farge, WI, USA
| | - Helena Lee
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
- Southampton Eye Unit, University Hospital Southampton NHS Foundation Trust, Southampton, UK
| | - N Simon Thomas
- Faculty of Medicine, University of Southampton, Southampton, UK
- Wessex Regional Genetics Laboratory, Salisbury District Hospital, Salisbury, UK
| | - Jonathan Callaway
- Faculty of Medicine, University of Southampton, Southampton, UK
- Wessex Regional Genetics Laboratory, Salisbury District Hospital, Salisbury, UK
| | - James Deline
- Center for Special Children, Vernon Memorial Healthcare, La Farge, WI, USA
| | - J Arjuna Ratnayaka
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Diana Baralle
- Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Melanie A Schmitt
- University of Wisconsin School of Medicine and Public Health, Department of Ophthalmology & Visual Sciences, Madison, WI, USA
| | - Chelsea S Norman
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
- The Rosalind Franklin Institute, Rutherford Appleton Laboratories, Harwell Science and Innovation Campus, Didcot, UK
| | - Sheri Hammond
- Center for Special Children, Vernon Memorial Healthcare, La Farge, WI, USA
| | - Gaurav V Harlalka
- RILD Wellcome Wolfson Centre, Royal Devon & Exeter NHS Foundation Trust, Barrack Road, Exeter, UK
- Rajarshi Shahu College of Pharmacy, Malvihir, Buldana, India
| | - Sarah Ennis
- Department of Human Genetics and Genomic Medicine, University of Southampton, Southampton, UK
| | - Harold E Cross
- Department of Ophthalmology, University of Arizona College of Medicine, Tucson, AZ, USA
| | - Olivia Wenger
- New Leaf Clinic, PO Box 336, 16014 East Chestnut Street, Mount Eaton, OH, 44691, USA
- Department of Pediatrics, Akron Children's Hospital, 214 West Bowery Street, Akron, OH, 44308, USA
| | - Andrew H Crosby
- RILD Wellcome Wolfson Centre, Royal Devon & Exeter NHS Foundation Trust, Barrack Road, Exeter, UK.
| | - Emma L Baple
- RILD Wellcome Wolfson Centre, Royal Devon & Exeter NHS Foundation Trust, Barrack Road, Exeter, UK.
- Peninsula Clinical Genetics Service, Royal Devon & Exeter Hospital (Heavitree), Gladstone Road, Exeter, UK.
| | - Jay E Self
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK.
- Southampton Eye Unit, University Hospital Southampton NHS Foundation Trust, Southampton, UK.
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42
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Kruijt CC, Gradstein L, Bergen AA, Florijn RJ, Arveiler B, Lasseaux E, Zanlonghi X, Bagdonaite-Bejarano L, Fulton AB, Yahalom C, Blumenfeld A, Perez Y, Birk OS, de Wit GC, Schalij-Delfos NE, van Genderen MM. The Phenotypic and Mutational Spectrum of the FHONDA Syndrome and Oculocutaneous Albinism: Similarities and Differences. Invest Ophthalmol Vis Sci 2022; 63:19. [PMID: 35029636 PMCID: PMC8762694 DOI: 10.1167/iovs.63.1.19] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Purpose The purpose of this study was to further expand the mutational spectrum of the Foveal Hypoplasia, Optic Nerve Decussation defect, and Anterior segment abnormalities (FHONDA syndrome), to describe the phenotypic spectrum, and to compare it to albinism. Subjects and Methods We retrospectively collected molecular, ophthalmic, and electrophysiological data of 28 patients molecularly confirmed with FHONDA from the Netherlands (9), Israel (13), France (2), and the United States of America (4). We compared the data to that of 133 Dutch patients with the 3 most common types of albinism in the Netherlands: oculocutaneous albinism type 1 (49), type 2 (41), and ocular albinism (43). Results Patients with FHONDA had a total of 15 different mutations in SLC38A8, of which 6 were novel. Excluding missing data, all patients had moderate to severe visual impairment (median visual acuity [VA] = 0.7 logMAR, interquartile range [IQR] = 0.6-0.8), nystagmus (28/28), and grade 4 foveal hypoplasia (17/17). Misrouting was present in all nine tested patients. None of the patients had any signs of hypopigmentation of skin and hair. VA in albinism was better (median = 0.5 logMAR, IQR = 0.3-0.7, P 0.006) and the phenotypes were more variable: 14 of 132 without nystagmus, foveal hypoplasia grades 1 to 4, and misrouting absent in 16 of 74. Conclusions Compared to albinism, the FHONDA syndrome appears to have a more narrow phenotypic spectrum, consisting of nonprogressive moderately to severely reduced VA, nystagmus, severe foveal hypoplasia, and misrouting. The co-occurrence of nystagmus, foveal hypoplasia, and misrouting in the absence of hypopigmentation implies that these abnormalities are not caused by lack of melanin, which has important implications for understanding the pathogenesis of these features.
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Affiliation(s)
- Charlotte C Kruijt
- Bartiméus Diagnostic Center for Complex Visual Disorders, Zeist, The Netherlands.,Department of Ophthalmology, Leiden University Medical Center, Leiden, The Netherlands
| | - Libe Gradstein
- Department of Ophthalmology, Soroka Medical Center and Clalit Health Services, Faculty of Health Sciences, Ben Gurion University of the Negev, Beer Sheva, Israel
| | - Arthur A Bergen
- Department of Human Genetics, Amsterdam University Medical Center, Location AMC, Amsterdam, The Netherlands.,The Netherlands Institute for Neurosciences (NIN-KNAW), Amsterdam, The Netherlands.,Department of Ophthalmology, Academic Medical Center, Amsterdam, The Netherlands
| | - Ralph J Florijn
- Department of Human Genetics, Amsterdam University Medical Center, Location AMC, Amsterdam, The Netherlands
| | - Benoit Arveiler
- Maladies Rares: Génétique et Métabolisme (MRGM), Inserm U1211, University of Bordeaux, Bordeaux, France.,Department of Medical Genetics, CHU Bordeaux, Bordeaux, France
| | | | - Xavier Zanlonghi
- Centre de Compétence Maladie Rares, Clinique Pluridisciplinaire Jules Verne, Nantes, France
| | | | - Anne B Fulton
- Department of Ophthalmology, Boston Children's Hospital, Boston, Massachusetts, United States.,Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States
| | - Claudia Yahalom
- Faculty of Medicine, Hebrew University of Jerusalem, Israel; Department of Ophthalmology, Hadassah Medical Center, Jerusalem, Israel
| | - Anat Blumenfeld
- Faculty of Medicine, Hebrew University of Jerusalem, Israel; Department of Ophthalmology, Hadassah Medical Center, Jerusalem, Israel
| | - Yonatan Perez
- The Morris Kahn Laboratory of Human Genetics, National Institute for Biotechnology in the Negev and Faculty of Health Sciences, Ben Gurion University of the Negev, Beer Sheva, Israel
| | - Ohad S Birk
- The Morris Kahn Laboratory of Human Genetics, National Institute for Biotechnology in the Negev and Faculty of Health Sciences, Ben Gurion University of the Negev, Beer Sheva, Israel.,Genetics Institute, Soroka Medical Center, Ben Gurion University of the Negev, Beer Sheva, Israel
| | - Gerard C de Wit
- Bartiméus Diagnostic Center for Complex Visual Disorders, Zeist, The Netherlands
| | | | - Maria M van Genderen
- Bartiméus Diagnostic Center for Complex Visual Disorders, Zeist, The Netherlands.,Department of Ophthalmology, University Medical Center Utrecht, Utrecht, The Netherlands
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43
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Puzniak RJ, Prabhakaran GT, Hoffmann MB. Deep Learning-Based Detection of Malformed Optic Chiasms From MRI Images. Front Neurosci 2021; 15:755785. [PMID: 34759795 PMCID: PMC8573410 DOI: 10.3389/fnins.2021.755785] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 09/16/2021] [Indexed: 11/18/2022] Open
Abstract
Convolutional neural network (CNN) models are of great promise to aid the segmentation and analysis of brain structures. Here, we tested whether CNN trained to segment normal optic chiasms from the T1w magnetic resonance imaging (MRI) image can be also applied to abnormal chiasms, specifically with optic nerve misrouting as typical for human albinism. We performed supervised training of the CNN on the T1w images of control participants (n = 1049) from the Human Connectome Project (HCP) repository and automatically generated algorithm-based optic chiasm masks. The trained CNN was subsequently tested on data of persons with albinism (PWA; n = 9) and controls (n = 8) from the CHIASM repository. The quality of outcome segmentation was assessed via the comparison to manually defined optic chiasm masks using the Dice similarity coefficient (DSC). The results revealed contrasting quality of masks obtained for control (mean DSC ± SEM = 0.75 ± 0.03) and PWA data (0.43 ± 0.8, few-corrected p = 0.04). The fact that the CNN recognition of the optic chiasm fails for chiasm abnormalities in PWA underlines the fundamental differences in their spatial features. This finding provides proof of concept for a novel deep-learning-based diagnostics approach of chiasmal misrouting from T1w images, as well as further analyses on chiasmal misrouting and their impact on the structure and function of the visual system.
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Affiliation(s)
- Robert J Puzniak
- Visual Processing Lab, Department of Ophthalmology, Otto-von-Guericke-University, Magdeburg, Germany
| | - Gokulraj T Prabhakaran
- Visual Processing Lab, Department of Ophthalmology, Otto-von-Guericke-University, Magdeburg, Germany
| | - Michael B Hoffmann
- Visual Processing Lab, Department of Ophthalmology, Otto-von-Guericke-University, Magdeburg, Germany.,Center for Behavioral Brain Sciences, Otto-von-Guericke-University, Magdeburg, Germany
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44
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Aamir A, Kuht HJ, Grønskov K, Brooks BP, Thomas MG. Clinical utility gene card for oculocutaneous (OCA) and ocular albinism (OA)-an update. Eur J Hum Genet 2021; 29:1577-1583. [PMID: 33504991 PMCID: PMC8484472 DOI: 10.1038/s41431-021-00809-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 12/12/2020] [Accepted: 01/08/2021] [Indexed: 02/07/2023] Open
Affiliation(s)
- Abdullah Aamir
- The University of Leicester Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University of Leicester, RKCSB, PO Box 65, Leicester, LE2 7LX, UK
| | - Helen J Kuht
- The University of Leicester Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University of Leicester, RKCSB, PO Box 65, Leicester, LE2 7LX, UK
| | - Karen Grønskov
- Rigshospitalet, Department of Clinical Genetics, Kennedy Center, Copenhagen University Hospital, Glostrup, Denmark
| | - Brian P Brooks
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, Bethesda, MD, USA
| | - Mervyn G Thomas
- The University of Leicester Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University of Leicester, RKCSB, PO Box 65, Leicester, LE2 7LX, UK.
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45
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Dumitrescu AV, Pfeifer WL, Drack AV. Clinical phenocopies of albinism. J AAPOS 2021; 25:220.e1-220.e8. [PMID: 34280564 DOI: 10.1016/j.jaapos.2021.03.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 02/28/2021] [Accepted: 03/07/2021] [Indexed: 10/20/2022]
Abstract
PURPOSE To present a series of patients diagnosed with oculocutaneous albinism (OCA) based on clinical presentation who were later proven to have a different diagnosis. METHODS The medical records of patients seen at the Pediatric Inherited Eye Disease Clinic of the University of Iowa from 1980 to 2018 who were eventually discovered to have an incorrect diagnosis of OCA were reviewed retrospectively. RESULTS Eight pediatric patients presenting with clinical features suggestive of OCA which changed to a different diagnosis over time were identified. Presenting clinical features included fair pigmentation of the skin and adnexa (8/8), congenital nystagmus (6/8), decreased visual acuity (8/8), iris transillumination defects (8/8), and foveal hypoplasia (7/8). Of the 8 patients, 4 manifested progressive, preschool-age-onset myopia. Other associated clinical features included hearing loss (3), seizures (1), abnormal chest x-ray (1) and easy bruising (2). During follow-up, additional clinical features and genetic testing proved that they have different clinical entities, namely, Knobloch syndrome, Jeune syndrome, Donnai-Barrow syndrome, Waardenburg syndrome, Aniridia syndrome, Stickler syndrome, and Hermansky-Pudlak syndrome, one of the syndromic types of OCA. CONCLUSIONS Clinical features used to diagnose OCA also occur in other disorders. For a definitive diagnosis of OCA, ancillary/genetic testing must be performed. Clinical features not typically found in association with albinism, such as hearing loss, or early onset, or progressive myopia, may indicate the need for more extensive investigation.
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Affiliation(s)
- Alina V Dumitrescu
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, University of Iowa, Iowa City.
| | - Wanda L Pfeifer
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, University of Iowa, Iowa City
| | - Arlene V Drack
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, University of Iowa, Iowa City
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46
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Dumitrescu AV, Tran J, Pfeifer W, Bhattarai SV, Kemerley A, Dunn TV, Wang K, Scheetz TE, Drack A. Clinical albinism score, presence of nystagmus and optic nerves defects are correlated with visual outcome in patients with oculocutaneous albinism. Ophthalmic Genet 2021; 42:539-552. [PMID: 34251969 DOI: 10.1080/13816810.2021.1933544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Purpose: To correlate clinical features, molecular genetic findings, and visual acuity in a cohort of patients clinically diagnosed with oculocutaneous albinism.Design: Retrospective chart reviewMethods: 58 charts met the inclusion criteria. Clinical examination, ancillary testing, and molecular genetic diagnoses were extracted. A novel clinical albinism score (CAS) was developed.Results: A least one likely pathogenic mutation was found in 44/58 (75.9%) patients. Mutations in the OCA1 gene were the most common (52.3%), followed by OCA2 (34%), OCA4 (2.3%), OA1 (6.8%), and HPS (4.5%). Thirty-four percentage of patients had a complete genotype, 41% had one mutation found and 24% had negative genetic testing. CAS was statistically significantly higher in patients with complete genotype, versus patients with one or no mutations found (p < .01). Better visual acuity was associated with lower CAS and fewer disease-causing mutations (p < .01). Foveal defects and iris transillumination were associated with a higher number of mutations (p < .01). Patients with nystagmus or anomalous optic nerves had worse visual acuity than those who did not (p < .01, p < .05).Conclusions: Patients with a complete genotype were more likely to have higher CAS. Vision loss correlated with complete phenotype and higher CAS, the presence of nystagmus and anomalous optic nerves. Patients with features of albinism in whom an incomplete genotype was found had better vision than those with complete genotype, suggesting a mild occult mutation or modifier variant. Genetic diagnosis is vital for complete diagnosis, counseling, and family planning.
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Affiliation(s)
- Alina V Dumitrescu
- Department of Ophthalmology and Visual Science, University of Iowa, Iowa City, IA, USA.,Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Johnny Tran
- Institute for Vision Research, University of Iowa, Iowa City, IA, USA
| | - Wanda Pfeifer
- Department of Ophthalmology and Visual Science, University of Iowa, Iowa City, IA, USA
| | - Sajag V Bhattarai
- Institute for Vision Research, University of Iowa, Iowa City, IA, USA
| | - Andrew Kemerley
- Institute for Vision Research, University of Iowa, Iowa City, IA, USA
| | - Taylor V Dunn
- Department of Ophthalmology and Visual Science, University of Iowa, Iowa City, IA, USA
| | - Kai Wang
- Department of Ophthalmology and Visual Science, University of Iowa, Iowa City, IA, USA
| | - Tod E Scheetz
- Institute for Vision Research, University of Iowa, Iowa City, IA, USA
| | - Arlene Drack
- Department of Ophthalmology and Visual Science, University of Iowa, Iowa City, IA, USA
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47
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Loftus SK, Lundh L, Watkins-Chow DE, Baxter LL, Pairo-Castineira E, Nisc Comparative Sequencing Program, Jackson IJ, Oetting WS, Pavan WJ, Adams DR. A custom capture sequence approach for oculocutaneous albinism identifies structural variant alleles at the OCA2 locus. Hum Mutat 2021; 42:1239-1253. [PMID: 34246199 DOI: 10.1002/humu.24257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 06/02/2021] [Accepted: 06/24/2021] [Indexed: 11/09/2022]
Abstract
Oculocutaneous albinism (OCA) is a heritable disorder of pigment production that manifests as hypopigmentation and altered eye development. Exon sequencing of known OCA genes is unsuccessful in producing a complete molecular diagnosis for a significant number of affected individuals. We sequenced the DNA of individuals with OCA using short-read custom capture sequencing that targeted coding, intronic, and noncoding regulatory regions of known OCA genes, and genome-wide association study-associated pigmentation loci. We identified an OCA2 complex structural variant (CxSV), defined by a 143 kb inverted segment reintroduced in intron 1, upstream of the native location. The corresponding CxSV junctions were observed in 11/390 probands screened. The 143 kb CxSV presents in one family as a copy number variant duplication for the 143 kb region. In the remaining 10/11 families, the 143 kb CxSV acquired an additional 184 kb deletion across the same region, restoring exons 3-19 of OCA2 to a copy-number neutral state. Allele-associated haplotype analysis found rare SNVs rs374519281 and rs139696407 are linked with the 143 kb CxSV in both OCA2 alleles. For individuals in which customary molecular evaluation does not reveal a biallelic OCA diagnosis, we recommend preliminary screening for these haplotype-associated rare variants, followed by junction-specific validation for the OCA2 143 kb CxSV.
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Affiliation(s)
- Stacie K Loftus
- Genetic Disease Research Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Linnea Lundh
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Dawn E Watkins-Chow
- Genetic Disease Research Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Laura L Baxter
- Genetic Disease Research Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Erola Pairo-Castineira
- Roslin Institute, University of Edinburgh, Easter Bush, Edinburgh, UK.,MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh, UK
| | | | - Ian J Jackson
- Roslin Institute, University of Edinburgh, Easter Bush, Edinburgh, UK.,MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh, UK
| | - William S Oetting
- Department of Experimental and Clinical Pharmacology, University of Minnesota, Minneapolis, Minnesota, USA
| | - William J Pavan
- Genetic Disease Research Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - David R Adams
- Office of the Clinical Director, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
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48
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Evident hypopigmentation without other ocular deficits in Dutch patients with oculocutaneous albinism type 4. Sci Rep 2021; 11:11572. [PMID: 34078970 PMCID: PMC8172864 DOI: 10.1038/s41598-021-90896-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 05/05/2021] [Indexed: 02/04/2023] Open
Abstract
To describe the phenotype of Dutch patients with oculocutaneous albinism type 4 (OCA4), we collected data on pigmentation (skin, hair, and eyes), visual acuity (VA), nystagmus, foveal hypoplasia, chiasmal misrouting, and molecular analyses of nine Dutch OCA4 patients from the Bartiméus Diagnostic Center for complex visual disorders. All patients had severely reduced pigmentation of skin, hair, and eyes with iris transillumination over 360 degrees. Three unrelated OCA4 patients had normal VA, no nystagmus, no foveal hypoplasia, and no misrouting of the visual pathways. Six patients had poor visual acuity (0.6 to 1.0 logMAR), nystagmus, severe foveal hypoplasia and misrouting. We found two novel variants in the SLC45A2 gene, c.310C > T; (p.Pro104Ser), and c.1368 + 3_1368 + 9del; (p.?). OCA4 patients of this Dutch cohort all had hypopigmentation of skin, hair, and iris translucency. However, patients were either severely affected with regard to visual acuity, foveal hypoplasia, and misrouting, or visually not affected at all. We describe for the first time OCA4 patients with an evident lack of pigmentation, but normal visual acuity, normal foveal development and absence of misrouting. This implies that absence of melanin does not invariably lead to foveal hypoplasia and abnormal routing of the visual pathways.
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49
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Moreno-Artero E, Morice-Picard F, Bremond-Gignac D, Drumare-Bouvet I, Duncombe-Poulet C, Leclerc-Mercier S, Dufresne H, Kaplan J, Jouanne B, Arveiler B, Taieb A, Hadj-Rabia S. Management of albinism: French guidelines for diagnosis and care. J Eur Acad Dermatol Venereol 2021; 35:1449-1459. [PMID: 34042219 DOI: 10.1111/jdv.17275] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 03/22/2021] [Indexed: 12/12/2022]
Abstract
Albinism is a worldwide genetic disorder caused by mutations in at least 20 genes, identified to date, that affect melanin production or transport in the skin, hair and eyes. Patients present with variable degrees of diffuse muco-cutaneous and adnexal hypopigmentation, as well as ocular features including nystagmus, misrouting of optic nerves and foveal hypoplasia. Less often, albinism is associated with blood, immunological, pulmonary, digestive and/or neurological anomalies. Clinical and molecular characterizations are essential in preventing potential complications. Disease-causing mutations remain unknown for about 25% of patients with albinism. These guidelines have been developed for the diagnosis and management of syndromic and non-syndromic forms of albinism, based on a systematic review of the scientific literature. These guidelines comprise clinical and molecular characterization, diagnosis, therapeutic approach and management.
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Affiliation(s)
- E Moreno-Artero
- Department of Dermatology, Reference Center for Genodermatoses and Rare Skin Diseases (MAGEC), Hôpital Universitaire Necker- Enfants Malades, Assistance Publique - Hôpitaux de Paris-Centre (AP-HP5), Paris, France
| | - F Morice-Picard
- Pediatric Dermatology Unit, National Centre for Rare Skin Disorders, Hôpital Pellegrin-Enfants, CHU de Bordeaux, Bordeaux, France
| | - D Bremond-Gignac
- Department of Ophthalmology, Reference Centre for Rare Ocular Diseases (OPHTARA), Hôpital Necker-Enfants Malades, APHP5, Paris, France.,Université de Paris-Centre, Paris, France
| | - I Drumare-Bouvet
- Service d'exploration de la vision et neuro-ophtalmologie, CHRU de Lille, Lille, France
| | | | - S Leclerc-Mercier
- Department of Pathology, Hôpital Necker-Enfants Malades, APHP5, Reference Center for Genodermatoses and Rare Skin Diseases (MAGEC), Université de Paris-Centre, Paris, France
| | - H Dufresne
- Department of Dermatology, Reference Center for Genodermatoses and Rare Skin Diseases (MAGEC), Hôpital Universitaire Necker- Enfants Malades, Assistance Publique - Hôpitaux de Paris-Centre (AP-HP5), Paris, France.,Service Social Pédiatrique, Hôpital Necker-Enfants Malades, APHP5, Université de Paris-Centre, Paris, France
| | - J Kaplan
- Laboratory of Genetics in Ophthalmology, Imagine Institute, Paris, France
| | - B Jouanne
- French Association for Albinism (Genespoir), Rennes, France
| | - B Arveiler
- Molecular Genetics Laboratory, CHU de Bordeaux, Bordeaux, France.,INSERM U1211, Maladies Rares, Génétique et Métabolisme, Bordeaux, France
| | - A Taieb
- Pediatric Dermatology Unit, National Centre for Rare Skin Disorders, Hôpital Pellegrin-Enfants, CHU de Bordeaux, Bordeaux, France
| | - S Hadj-Rabia
- Department of Dermatology, Reference Center for Genodermatoses and Rare Skin Diseases (MAGEC), Hôpital Universitaire Necker- Enfants Malades, Assistance Publique - Hôpitaux de Paris-Centre (AP-HP5), Paris, France.,Université de Paris-Centre, Paris, France
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50
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Duwell EJ, Woertz EN, Mathis J, Carroll J, DeYoe EA. Aberrant visual population receptive fields in human albinism. J Vis 2021; 21:19. [PMID: 34007988 PMCID: PMC8142699 DOI: 10.1167/jov.21.5.19] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Retinotopic organization is a fundamental feature of visual cortex thought to play a vital role in encoding spatial information. One important aspect of normal retinotopy is the representation of the right and left hemifields in contralateral visual cortex. However, in human albinism, many temporal retinal afferents decussate aberrantly at the optic chiasm resulting in partially superimposed representations of opposite hemifields in each hemisphere of visual cortex. Previous functional magnetic resonance imaging (fMRI) studies in human albinism suggest that the right and left hemifield representations are superimposed in a mirror-symmetric manner. This should produce imaging voxels which respond to two separate locations mirrored across the vertical meridian. However, it is not yet clear how retino-cortical miswiring in albinism manifests at the level of single voxel population receptive fields (pRFs). Here, we used pRF modeling to fit both single and dual pRF models to the visual responses of voxels in visual areas V1 to V3 of five subjects with albinism. We found that subjects with albinism (but not controls) have sizable clusters of voxels with unequivocal dual pRFs consistently corresponding to, but not fully coextensive with, regions of hemifield overlap. These dual pRFs were typically positioned at locations roughly mirrored across the vertical meridian and were uniquely clustered within a portion of the visual field for each subject.
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Affiliation(s)
- Ethan J Duwell
- Department of Biophysics, Medical College of Wisconsin, Milwaukee, WI, USA.,
| | - Erica N Woertz
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA.,
| | - Jedidiah Mathis
- Department of Neurology, Medical College of Wisconsin, USA.,
| | - Joseph Carroll
- Department of Biophysics, Medical College of Wisconsin, Milwaukee, WI, USA.,Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA.,Department of Ophthalmology and Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA.,
| | - Edgar A DeYoe
- Department of Radiology, Medical College of Wisconsin, Milwaukee, WI, USA.,
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