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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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2
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Chang Y, Wu S, Li J, Bao H, Wu C. Identification of Candidate Genes for Red-Eyed (Albinism) Domestic Guppies Using Genomic and Transcriptomic Analyses. Int J Mol Sci 2024; 25:2175. [PMID: 38396851 PMCID: PMC10888696 DOI: 10.3390/ijms25042175] [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: 12/15/2023] [Revised: 02/05/2024] [Accepted: 02/07/2024] [Indexed: 02/25/2024] Open
Abstract
Guppies are small tropical fish with brightly colored bodies and variable tail shapes. There are two phenotypes of domestic guppy eye color: red and black. The wild type is black-eyed. The main object of this study was to identify candidate genes for the red-eyed phenotype in domestic guppies. We hope to provide molecular genetic information for the development of new domestic guppy strains. Additionally, the results also contribute to basic research concerning guppies. In this study, 121 domestic guppies were used for genomic analysis (GWAS), and 44 genes were identified. Furthermore, 21 domestic guppies were used for transcriptomic analysis, and 874 differentially expressed genes (DEGs) were identified, including 357 upregulated and 517 downregulated genes. Through GO and KEGG enrichment, we identified some important terms or pathways mainly related to melanin biosynthesis and ion transport. qRT-PCR was also performed to verify the differential expression levels of four important candidate genes (TYR, OCA2, SLC45A2, and SLC24A5) between red-eyed and black-eyed guppies. Based on the results of genomic and transcriptomic analyses, we propose that OCA2 is the most important candidate gene for the red-eyed phenotype in guppies.
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Affiliation(s)
| | | | | | - Haigang Bao
- National Engineering Laboratory for Animal Breeding, Beijing Key Laboratory for Animal Genetic Improvement, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China; (Y.C.); (S.W.); (J.L.); (C.W.)
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3
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Ang KC, Canfield VA, Foster TC, Harbaugh TD, Early KA, Harter RL, Reid KP, Leong SL, Kawasawa Y, Liu D, Hawley JW, Cheng KC. Native American genetic ancestry and pigmentation allele contributions to skin color in a Caribbean population. eLife 2023; 12:e77514. [PMID: 37294081 PMCID: PMC10371226 DOI: 10.7554/elife.77514] [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: 02/02/2022] [Accepted: 06/08/2023] [Indexed: 06/10/2023] Open
Abstract
Our interest in the genetic basis of skin color variation between populations led us to seek a Native American population with genetically African admixture but low frequency of European light skin alleles. Analysis of 458 genomes from individuals residing in the Kalinago Territory of the Commonwealth of Dominica showed approximately 55% Native American, 32% African, and 12% European genetic ancestry, the highest Native American genetic ancestry among Caribbean populations to date. Skin pigmentation ranged from 20 to 80 melanin units, averaging 46. Three albino individuals were determined to be homozygous for a causative multi-nucleotide polymorphism OCA2NW273KV contained within a haplotype of African origin; its allele frequency was 0.03 and single allele effect size was -8 melanin units. Derived allele frequencies of SLC24A5A111T and SLC45A2L374F were 0.14 and 0.06, with single allele effect sizes of -6 and -4, respectively. Native American genetic ancestry by itself reduced pigmentation by more than 20 melanin units (range 24-29). The responsible hypopigmenting genetic variants remain to be identified, since none of the published polymorphisms predicted in prior literature to affect skin color in Native Americans caused detectable hypopigmentation in the Kalinago.
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Affiliation(s)
- Khai C Ang
- Department of Pathology, Penn State College of MedicineHersheyUnited States
- Jake Gittlen Laboratories for Cancer Research, Penn State College of MedicineHersheyUnited States
| | - Victor A Canfield
- Department of Pathology, Penn State College of MedicineHersheyUnited States
- Jake Gittlen Laboratories for Cancer Research, Penn State College of MedicineHersheyUnited States
| | - Tiffany C Foster
- Department of Pathology, Penn State College of MedicineHersheyUnited States
- Jake Gittlen Laboratories for Cancer Research, Penn State College of MedicineHersheyUnited States
| | - Thaddeus D Harbaugh
- Department of Pathology, Penn State College of MedicineHersheyUnited States
- Jake Gittlen Laboratories for Cancer Research, Penn State College of MedicineHersheyUnited States
| | - Kathryn A Early
- Department of Pathology, Penn State College of MedicineHersheyUnited States
- Jake Gittlen Laboratories for Cancer Research, Penn State College of MedicineHersheyUnited States
| | - Rachel L Harter
- Department of Pathology, Penn State College of MedicineHersheyUnited States
| | - Katherine P Reid
- Department of Pathology, Penn State College of MedicineHersheyUnited States
- Jake Gittlen Laboratories for Cancer Research, Penn State College of MedicineHersheyUnited States
| | - Shou Ling Leong
- Department of Family & Community Medicine, Penn State College of MedicineHersheyUnited States
| | - Yuka Kawasawa
- Department of Biochemistry and Molecular Biology, Penn State College of MedicineHersheyUnited States
- Department of Pharmacology, Penn State College of MedicineHersheyUnited States
- Institute of Personalized Medicine, Penn State College of MedicineHersheyUnited States
| | - Dajiang Liu
- Department of Biochemistry and Molecular Biology, Penn State College of MedicineHersheyUnited States
- Department of Public Health Sciences, Penn State College of MedicineHersheyUnited States
| | | | - Keith C Cheng
- Department of Pathology, Penn State College of MedicineHersheyUnited States
- Jake Gittlen Laboratories for Cancer Research, Penn State College of MedicineHersheyUnited States
- Department of Biochemistry and Molecular Biology, Penn State College of MedicineHersheyUnited States
- Department of Pharmacology, Penn State College of MedicineHersheyUnited States
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4
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Huang X, Jia Y, Yang Y, Qu J, Pan B. Whole genome sequencing analysis of four patients: Are de novo copy number variations in non-coding region responsible for microtia with lung hypoplasia? Int J Pediatr Otorhinolaryngol 2023; 171:111626. [PMID: 37329699 DOI: 10.1016/j.ijporl.2023.111626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 05/04/2023] [Accepted: 06/05/2023] [Indexed: 06/19/2023]
Abstract
BACKGROUND Microtia is a congenital malformation of the out ear, occurring either as an isolated defect or part of a specific pattern of multiple congenital anomalies. The etiology of microtia is poorly understood. Four patients with microtia and lung hypoplasia were reported by our team in a previous article. The purpose of this study was to identify the underlying genetic basis, mainly focusing on de novo copy number variations (CNVs) embedded in the noncoding region, in the four subjects. METHODS DNA samples from all four patients and their unaffected parents were extracted for whole-genome sequencing on the Illumina platform. All variants were obtained through data quality control, variant calling and bioinformatics analysis. De novo strategy was used to prioritize the variants, and candidate variants were verified by PCR amplification combined with Sanger sequencing and visual inspection of bam file. RESULTS Whole gene sequencing following bioinformatics analysis showed no potential de novo pathogenic variants in the coding region. Nonetheless, four de novo CNVs in the non-coding region, intronic or intergenic, were identified in each subject, ranging in size from 10 Kb to 12.5 Kb, and all are deletions. Case 1 had a de novo deletion of 10 Kb on chromosome10q22.3, located in the intronic region of the LRMDA gene. The other three cases all had a de novo deletion in intergenic regions, located on chromosome 20q11.21, 7q31.1 and 13q12.13, respectively. CONCLUSIONS This study reported multiple long-lived cases of microtia with pulmonary hypoplasia and provided genome-wide genetic analysis focusing on de novo mutations. Whether the de novo CNVs identified are responsible for the rare phenotypes remains an open question. However, the results of our study provided a new perspective that the unsolved etiology of microtia might involve in non-coding sequences, which have long been ignored.
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Affiliation(s)
- Xin Huang
- Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, 100043, Beijing, People's Republic of China
| | - Yang Jia
- Department of Plastic Surgery, The Second Hospital of Hebei Medical University, 050000, Shijiazhuang, People's Republic of China
| | - Yang Yang
- Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, 100043, Beijing, People's Republic of China
| | - Jianwen Qu
- Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, 100043, Beijing, People's Republic of China
| | - Bo Pan
- Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, 100043, Beijing, People's Republic of China.
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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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Bi H, Tranell J, Harper DC, Lin W, Li J, Hellström AR, Larsson M, Rubin CJ, Wang C, Sayyab S, Kerje S, Bed’hom B, Gourichon D, Ito S, Wakamatsu K, Tixier-Boichard M, Marks MS, Globisch D, Andersson L. A frame-shift mutation in COMTD1 is associated with impaired pheomelanin pigmentation in chicken. PLoS Genet 2023; 19:e1010724. [PMID: 37068079 PMCID: PMC10138217 DOI: 10.1371/journal.pgen.1010724] [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: 12/22/2022] [Revised: 04/27/2023] [Accepted: 03/28/2023] [Indexed: 04/18/2023] Open
Abstract
The biochemical pathway regulating the synthesis of yellow/red pheomelanin is less well characterized than the synthesis of black/brown eumelanin. Inhibitor of gold (IG phenotype) is a plumage colour variant in chicken that provides an opportunity to further explore this pathway since the recessive allele (IG) at this locus is associated with a defect in the production of pheomelanin. IG/IG homozygotes display a marked dilution of red pheomelanin pigmentation, whilst black pigmentation (eumelanin) is only slightly affected. Here we show that a 2-base pair insertion (frame-shift mutation) in the 5th exon of the Catechol-O-methyltransferase containing domain 1 gene (COMTD1), expected to cause a complete or partial loss-of-function of the COMTD1 enzyme, shows complete concordance with the IG phenotype within and across breeds. We show that the COMTD1 protein is localized to mitochondria in pigment cells. Knockout of Comtd1 in a mouse melanocytic cell line results in a reduction in pheomelanin metabolites and significant alterations in metabolites of glutamate/glutathione, riboflavin, and the tricarboxylic acid cycle. Furthermore, COMTD1 overexpression enhanced cellular proliferation following chemical-induced transfection, a potential inducer of oxidative stress. These observations suggest that COMTD1 plays a protective role for melanocytes against oxidative stress and that this supports their ability to produce pheomelanin.
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Affiliation(s)
- Huijuan Bi
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Jonas Tranell
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Dawn C. Harper
- Department of Pathology & Laboratory Medicine and Department of Physiology, Children’s Hospital of Philadelphia and University of Pennsylvania Perelman School of Medicine, Philadelphia, United States of America
| | - Weifeng Lin
- Department of Chemistry - BMC, Uppsala University, Uppsala, Sweden
| | - Jingyi Li
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Anders R. Hellström
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Mårten Larsson
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Carl-Johan Rubin
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Chao Wang
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Shumaila Sayyab
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Susanne Kerje
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Bertrand Bed’hom
- Université Paris-Saclay, INRAE, AgroParisTech, GABI, F-78350 Jouy-en-Josas, France
| | | | - Shosuke Ito
- Institute for Melanin Chemistry, Fujita Health University, Toyoake, Aichi, Japan
| | - Kazumasa Wakamatsu
- Institute for Melanin Chemistry, Fujita Health University, Toyoake, Aichi, Japan
| | | | - Michael S. Marks
- Department of Pathology & Laboratory Medicine and Department of Physiology, Children’s Hospital of Philadelphia and University of Pennsylvania Perelman School of Medicine, Philadelphia, United States of America
| | - Daniel Globisch
- Department of Chemistry - BMC, Uppsala University, Uppsala, Sweden
| | - Leif Andersson
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, United States of America
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7
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Ma EZ, Zhou AE, Hoegler KM, Khachemoune A. Oculocutaneous albinism: epidemiology, genetics, skin manifestation, and psychosocial issues. Arch Dermatol Res 2023; 315:107-116. [PMID: 35217926 DOI: 10.1007/s00403-022-02335-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 01/06/2022] [Accepted: 02/10/2022] [Indexed: 11/29/2022]
Abstract
Oculocutaneous albinism (OCA) is a group of rare, inherited disorders associated with reduced melanin biosynthesis. Clinical manifestations of the eight known subtypes of OCA include hypopigmented skin, eyes, and hair and ocular manifestations, such as decreased visual acuity and nystagmus. OCA affects people globally but is most prevalent in African countries. Individuals with oculocutaneous albinism lack UV protection and are prone to skin damage and skin cancers. For many African albino individuals, there are significant challenges in seeking treatment for skin cancer and preventing sun damage due to psychosocial factors and poor education. This review summarizes the current understanding of the epidemiology, genetics, and clinical manifestations of OCA. We also discuss the medical and psychosocial challenges that affect individuals with OCA and the current landscape of albinism treatment modalities. The extent of the psychosocial challenges needs to be better understood and additional educational interventions may improve quality of life for people with albinism.
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Affiliation(s)
- Emily Z Ma
- Department of Dermatology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Albert E Zhou
- Department of Dermatology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Karl M Hoegler
- Department of Dermatology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Amor Khachemoune
- Brooklyn Campus of the VA NY Harbor Healthcare System, FACMS, 800 Poly Place, Brooklyn, NY, USA. .,Department of Dermatology, SUNY Downstate, 450 Clarkson Ave, Brooklyn, NY, USA.
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8
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Psychosocial implications of rare genetic skin diseases affecting appearance on daily life experiences, emotional state, self-perception and quality of life in adults: a systematic review. Orphanet J Rare Dis 2023; 18:39. [PMID: 36823650 PMCID: PMC9951542 DOI: 10.1186/s13023-023-02629-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 02/06/2023] [Indexed: 02/25/2023] Open
Abstract
BACKGROUND Since the beginning of human genetic research, there are very few publications sharing insights of the negative impact of rare genetic skin diseases (RGSD) on patients' experiences. This systematic review assessed the psychosocial implications of these conditions in terms of daily life experiences, emotional state, self-perception, and Quality of Life (QoL). METHODOLOGY A systematic review was carried out on albinism, neurofibromatosis type 1 (NF1), birthmarks and inherited ichthyosis. The PubMed, Scopus, PsycArticle, PsychInfo, Psychology and Behavioral Sciences Collection, and SOCindex databases were queried. Inclusion criteria were adult patients with one of these RGSDs. Simple descriptive statistics and qualitative content analysis were conducted to summarize the main results reported by the authors. RESULTS Of the 9987 articles retrieved, 48 articles were included: albinism (16), NF1 (16), inherited ichthyosis (10), birthmarks (6). The majority of the studies on albinism were conducted in Africa. Twenty-seven studies quantitatively assessed diverse psychological parameters: 13 showed a significant impact of the disease on QoL, five on emotional state, two on self-representation and two others on psychiatric comorbidities. Disease severity and visibility were good predictors of QoL (except for albinism). Body image and appearance concerns were also associated with QoL and emotional state. The 19 qualitative studies highlighted recurring themes across each of these diseases: discrimination and stigma during childhood and adolescence, discomfort in social interactions, guilt of transmission, the importance of social support from family and friends, altered daily life functioning, altered romantic and sex life, limited academic and professional aspirations, lack of interest and support from the medical field, and the unpredictability of the evolution of the disease. The only two mixed-method studies in this review were unable to contribute to any inferential analyses but could corroborate some of the qualitative findings. CONCLUSION These results showed that RGSDs have a significant impact on different aspects of patients' lives. This review has demonstrated that there is a real need for support systems for patients with these diseases. Such systems should be developed to provide them with necessary information and to guide them through an appropriate care pathway.
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9
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Chen X, Fang Z, Pang T, Li D, Lei J, Jiang W, Li H. Identification of novel variations of oculocutaneous albinism type 2 with Prader-Willi syndrome/Angelman syndrome in two Chinese families. Front Genet 2023; 14:1135698. [PMID: 36950135 PMCID: PMC10025288 DOI: 10.3389/fgene.2023.1135698] [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: 01/12/2023] [Accepted: 02/15/2023] [Indexed: 03/08/2023] Open
Abstract
Objective: Oculocutaneous albinism (OCA) is an autosomal recessive disorder caused by a variety of genomic variations. Our aim is to identify the molecular basis of OCA in two families and lay the foundation for prenatal diagnosis. Methods: Four types of OCA-causing mutations in the TYR, p, TYRP1, or SLC45A2 genes were screened. Linkage analysis was performed because the mutations found in the p gene violated the laws of classical Mendelian heredity. Primer-walking sequencing combined with microsatellite and single-nucleotide polymorphism analysis was used to ascertain deletion ranges. Bioinformatics methods were used to assess the pathogenicity of the new mutations. Results: Proband 1 was diagnosed as OCA2 with Prader-Willi syndrome (PWS) due to a novel atypical paternal deletion (chromosome 15: 22330347-26089649) and a pathogenic mutation, c.1327G>A (Val443Ile), in the p gene of the maternal chromosome. The prenatal diagnosis results for family 1 indicated the fetus was a heterozygous carrier (c.1327G>A in the p gene) with a normal phenotype. Proband 2 was diagnosed as OCA2 with Angelman syndrome (AS) due to a typical maternal deletion of chromosome 15q11-q13 and a novel mutation, c.1514T>C (Phe505Ser), in the p gene of the paternal chromosome. This novel mutation c.1514T>C (Phe505Ser) in the p gene was predicted as a pathogenic mutation. Conclusion: Our study has shown clear genotype-phenotype correlations in patients affected by distinct deletions of the PWS or AS region and missense mutations in the p gene. Our results have enriched the mutation spectrum of albinism diseases and provided insights for more accurate diagnosis and genetic counseling.
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Affiliation(s)
- XiaoFei Chen
- Maternity and Child Care Center of Dezhou, DeZhou, China
- Department of Medical Genetics, Zhongshan School of Medicine, Guangzhou, China
| | - ZiShui Fang
- Department of Medical Genetics, Zhongshan School of Medicine, Guangzhou, China
- Beijing Key Laboratory of Urogenital Diseases (Male) Molecular Diagnosis and Treatment Center, National Urological Cancer Center, Department of Urology, Peking University First Hospital, Institution of Urology, Peking University, Beijing, China
| | - Ting Pang
- Department of Medical Genetics, Zhongshan School of Medicine, Guangzhou, China
| | - DongZhi Li
- Prenatal Diagnosis Center, Guangzhou Women and Children’s Medical Center, Guangzhou, China
| | - Jie Lei
- Department of Medical Genetics, Zhongshan School of Medicine, Guangzhou, China
- Shenzhen Nanshan Maternity and Child Healthcare Hospital, Shenzhen, China
- *Correspondence: Jie Lei, ; WeiYing Jiang, ; HongYi Li,
| | - WeiYing Jiang
- Department of Medical Genetics, Zhongshan School of Medicine, Guangzhou, China
- *Correspondence: Jie Lei, ; WeiYing Jiang, ; HongYi Li,
| | - HongYi Li
- Department of Medical Genetics, Zhongshan School of Medicine, Guangzhou, China
- *Correspondence: Jie Lei, ; WeiYing Jiang, ; HongYi Li,
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10
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Beyers WC, Detry AM, Di Pietro SM. OCA7 is a melanosome membrane protein that defines pigmentation by regulating early stages of melanosome biogenesis. J Biol Chem 2022; 298:102669. [PMID: 36334630 DOI: 10.1016/j.jbc.2022.102669] [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: 06/15/2022] [Revised: 10/21/2022] [Accepted: 10/24/2022] [Indexed: 11/11/2022] Open
Abstract
Mutations in C10orf11 (oculocutaneous albinism type 7 [OCA7]) cause OCA, a disorder that presents with hypopigmentation in skin, eyes, and hair. The OCA7 pathophysiology is unknown, and there is virtually no information on the OCA7 protein and its cellular function. Here, we discover that OCA7 localizes to the limiting membrane of melanosomes, the specialized pigment cell organelles where melanin is synthesized. We demonstrate that OCA7 is recruited through interaction with a canonical effector-binding surface of melanosome proteins Rab32 and Rab38. Using newly generated OCA7-KO MNT1 cells, we show OCA7 regulates overall melanin levels in a melanocyte autonomous manner by controlling melanosome maturation. Importantly, we found that OCA7 regulates premelanosome protein (PMEL) processing, impacting fibrillation and the striations that define transition from melanosome stage I to stage II. Furthermore, the melanosome lumen of OCA7-KO cells displays lower pH than control cells. Together, our results reveal that OCA7 regulates pigmentation through two well-established determinants of melanosome biogenesis and function, PMEL processing, and organelle pH.
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Affiliation(s)
- Wyatt C Beyers
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado, USA
| | - Anna M Detry
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado, USA
| | - Santiago M Di Pietro
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado, USA.
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11
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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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12
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Pediatric Cutaneous Oncology. Dermatol Clin 2022; 41:175-185. [DOI: 10.1016/j.det.2022.07.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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13
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Ludwig-Słomczyńska AH, Seweryn MT, Radkowski P, Kapusta P, Machlowska J, Pruhova S, Gasperikova D, Bellanne-Chantelot C, Hattersley A, Kandasamy B, Letourneau-Freiberg L, Philipson L, Doria A, Wołkow PP, Małecki MT, Klupa T. Variants influencing age at diagnosis of HNF1A-MODY. Mol Med 2022; 28:113. [PMID: 36104811 PMCID: PMC9476297 DOI: 10.1186/s10020-022-00542-0] [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: 04/06/2022] [Accepted: 09/06/2022] [Indexed: 02/03/2023] Open
Abstract
BACKGROUND HNF1A-MODY is a monogenic form of diabetes caused by variants in the HNF1A gene. Different HNF1A variants are associated with differences in age of disease onset, but other factors are postulated to influence this trait. Here, we searched for genetic variants influencing age of HNF1A-MODY onset. METHODS Blood samples from 843 HNF1A-MODY patients from Czech Republic, France, Poland, Slovakia, the UK and the US were collected. A validation set consisted of 121 patients from the US. We conducted a genome-wide association study in 843 HNF1A-MODY patients. Samples were genotyped using Illumina Human Core arrays. The core analysis was performed using the GENESIS package in R statistical software. Kinship coefficients were estimated with the KING and PC-Relate algorithms. In the linear mixed model, we accounted for year of birth, sex, and location of the HNF1A causative variant. RESULTS A suggestive association with age of disease onset was observed for rs2305198 (p = 2.09E-07) and rs7079157 (p = 3.96E-06) in the HK1 gene, rs2637248 in the LRMDA gene (p = 2.44E-05), and intergenic variant rs2825115 (p = 2.04E-05). Variant rs2637248 reached nominal significance (p = 0.019), while rs7079157 (p = 0.058) and rs2825115 (p = 0.068) showed suggestive association with age at diabetes onset in the validation set. CONCLUSIONS rs2637248 in the LRMDA gene is associated with age at diabetes onset in HNF1A-MODY patients.
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Affiliation(s)
| | - Michał T. Seweryn
- grid.5522.00000 0001 2162 9631Center For Medical Genomics OMICRON, Jagiellonian University Medical College, Kraków, Poland ,grid.261331.40000 0001 2285 7943Department of Pharmacogenomics, The Ohio State University, Columbus, OH USA
| | - Piotr Radkowski
- grid.5522.00000 0001 2162 9631Center For Medical Genomics OMICRON, Jagiellonian University Medical College, Kraków, Poland
| | - Przemysław Kapusta
- grid.5522.00000 0001 2162 9631Center For Medical Genomics OMICRON, Jagiellonian University Medical College, Kraków, Poland
| | - Julita Machlowska
- grid.5522.00000 0001 2162 9631Center For Medical Genomics OMICRON, Jagiellonian University Medical College, Kraków, Poland
| | - Stepanka Pruhova
- grid.4491.80000 0004 1937 116XDepartment of Pediatrics, Charles University in Prague, Second Faculty of Medicine and University Hospital Motol, Prague, Czech Republic
| | - Daniela Gasperikova
- grid.419303.c0000 0001 2180 9405Institute of Experimental Endocrinology, Biomedical Research Center, Slovak Academy of Sciences, Bratislava, Slovakia
| | | | | | - Balamurugan Kandasamy
- grid.170205.10000 0004 1936 7822Kovler Diabetes Center, University of Chicago, Chicago, IL USA
| | | | - Louis Philipson
- grid.170205.10000 0004 1936 7822Kovler Diabetes Center, University of Chicago, Chicago, IL USA
| | - Alessandro Doria
- grid.38142.3c000000041936754XJoslin Diabetes Center, Harvard Medical School, Boston, MA USA
| | - Paweł P. Wołkow
- grid.5522.00000 0001 2162 9631Center For Medical Genomics OMICRON, Jagiellonian University Medical College, Kraków, Poland
| | - Maciej T. Małecki
- grid.5522.00000 0001 2162 9631Department of Metabolic Diseases, Jagiellonian University Medical College, Kraków, Poland
| | - Tomasz Klupa
- grid.5522.00000 0001 2162 9631Department of Metabolic Diseases, Jagiellonian University Medical College, Kraków, Poland
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14
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Ullah MI. Clinical and Mutation Spectrum of Autosomal Recessive Non-Syndromic Oculocutaneous Albinism (nsOCA) in Pakistan: A Review. Genes (Basel) 2022; 13:genes13061072. [PMID: 35741834 PMCID: PMC9222488 DOI: 10.3390/genes13061072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 06/09/2022] [Accepted: 06/13/2022] [Indexed: 02/01/2023] Open
Abstract
Oculocutaneous albinism (OCA) is an autosomal recessive syndromic and non-syndromic defect with deficient or a complete lack of the melanin pigment. The characteristics of OCA appears in skin, hair, and eyes with variable degree of pigmentation. Clinical manifestations of OCA include nystagmus, photophobia, reduced visual acuity, hypo-plastic macula, and iris trans-illumination. There are eight OCA types (OCA1–8) documented with non-syndromic characteristics. Molecular studies identified seven genes linked to the OCA phenotype (TYR, OCA2, TYRP1, SLC45A2, SLC24A5, C10orf11, and DCT) and one locus (OCA5) in consanguineous and sporadic albinism. The complications of OCA result in skin cancer and variable syndromes such as Hermansky–Pudlak syndrome (HPS) Chediak–Higashi syndrome (CHS). In the Pakistani population, autosomal recessive non-syndromic OCA is common and is associated with a large number of consanguineous families, and mutations in genes of non-syndromic types are reported. This review highlights the updates on the genetic mutation of OCA genes reported from Pakistani families. Several studies reported the genetic mutations in OCA1, OCA2, OCA3, OCA4, and OCA6 albinism in Pakistani families. A locus, OCA5, was also reported from the Pakistani population, but the gene has not been identified. A new type of OCA8 was identified due to the DCT gene mutation, and it is also reviewed here.
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Affiliation(s)
- Muhammad Ikram Ullah
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, Jouf University, Sakaka 75471, Aljouf, Saudi Arabia
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15
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Holm E, Holm M, Vilhelmsen K, Andorsdottir G, Vorum H, Simpson A, Roos BR, Fingert JH, Rosenberg T. Prevalence of Open-angle Glaucoma in the Faroese Population. J Glaucoma 2022; 31:72-78. [PMID: 34342283 PMCID: PMC8795462 DOI: 10.1097/ijg.0000000000001921] [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: 04/08/2021] [Accepted: 07/24/2021] [Indexed: 02/03/2023]
Abstract
PURPOSE The Faroe Islands are home to 50,000 genetically isolated people in the North Atlantic. The prevalence of open-angle glaucoma (OAG) in the Faroese population is unknown. Consequently, we conducted a survey to determine the prevalence of OAG in the Faroese population. We also investigated the role of known glaucoma-causing genes in Faroese OAG. MATERIALS AND METHODS We conducted a prospective survey of known and newly diagnosed glaucoma patients at the Faroese National Hospital, Landssjukrahusid, Tórshavn between October 1, 2015 to December 31, 2017. In addition we reviewed the only eye care provider in the Faroese Islands by scrutinizing electronic medical records between 2009 and June 15, 2014, October 1, 2015 and the partly overlapping prescriptions for ocular hypotensive medications in 2016 to identify patients with either a diagnosis of glaucoma, a diagnosis of ocular hypertension or a prescription for ocular hypotensive medications. Next, we prospectively confirmed diagnoses with complete eye examinations. Patient DNA samples were tested for variations in known glaucoma-causing genes [myocilin (MYOC), optineurin (OPTN), and TANK binding kinase 1 (TBK1)]. RESULTS We determined the age-related prevalence of OAG January 1, 2017 in individuals 40 years or older to be 10.7/1000 (1.07%) and highly age-related. A diagnosis of OAG was present in 264 patients, of whom 211 (79.9%) had primary OAG (including normal tension glaucoma), 49 (18.6%) had pseudoexfoliation glaucoma, and 4 (1.5%) had pigmentary glaucoma. Among patients receiving medications for glaucoma, nearly 50% had primary OAG, while the majority of the rest had ocular hypertension or secondary glaucoma. No disease-causing variants were detected in MYOC, OPTN, or TBK1. CONCLUSIONS The calculated prevalence of OAG in the Faroe Islands was 1.07%. The absence of MYOC, OPTN, or TBK1 disease-causing variants in Faroese primary OAG patients suggests that a different, potentially unique set of genes may be contributing to the pathogenesis of glaucoma in this population.
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Affiliation(s)
| | | | | | | | - Henrik Vorum
- Department of Ophthalmology, University Hospital, Aalborg
| | - Allie Simpson
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, University of Iowa, Iowa City, IA
| | - Benjamin R Roos
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, University of Iowa, Iowa City, IA
| | - John H Fingert
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, University of Iowa, Iowa City, IA
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16
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Dhangar S, Panchal P, Ghatanatti J, Suralkar J, Shah A, Vundinti BR. Novel deletion of exon 3 in TYR gene causing Oculocutaneous albinism 1B in an Indian family along with intellectual disability associated with chromosomal copy number variations. BMC Med Genomics 2022; 15:2. [PMID: 34980106 PMCID: PMC8722050 DOI: 10.1186/s12920-021-01152-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 12/20/2021] [Indexed: 12/13/2022] Open
Abstract
Background Oculocutaneous albinism (OCA) is an autosomal recessive disorder characterized by hypo-pigmentation of skin, hair, and eyes. The OCA clinical presentation is due to a deficiency of melanin biosynthesis. Intellectual disability (ID) in OCA cases is a rare clinical presentation and appropriate diagnosis of ID is challenging through clinical examination. We report an Indian family with a rare co-inheritance of OCA1B and ID due to a novel TYR gene variant and chromosomal copy number variations. Methods We have done a study on three siblings (2 males and 1 female) of a family where all of them presented with hypopigmented skin, hair and eyes. The male children and their father was affected with ID. Targeted exome sequencing and multiplex ligation-dependent probe amplification analysis were carried out to identify the OCA1B and ID associated genomic changes. Further Array-CGH was performed using SurePrint G3 Human CGH + SNP, 8*60 K array. Results A rare homozygous deletion of exon 3 in TYR gene causing OCA1B was identified in all three children. The parents were found to be heterozygous carriers. The Array-CGH analysis revealed paternally inherited heterozygous deletion (1.9 MB) of 15q11.1-> 15q11.2 region in all three children. Additionally, paternally inherited heterozygous deletion (2.6 MB) of 10q23.2-> 10q23.31 region was identified in the first male child; this may be associated with ID as the father and the child both presented with ID. While the 2nd male child had a denovo duplication of 13q31.1-> 13q31.3 chromosomal region. Conclusion A rare homozygous TYR gene exon 3 deletion in the present study is the cause of OCA1B in all three children, and the additional copy number variations are associated with the ID. The study highlights the importance of combinational genetic approaches for diagnosing two different co-inherited disorders (OCA and ID). Hence, OCA cases with additional clinical presentation need to be studied in-depth for the appropriate management of the disease. Supplementary Information The online version contains supplementary material available at 10.1186/s12920-021-01152-1.
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Affiliation(s)
- Somprakash Dhangar
- Department of Cytogenetics, National Institute of Immunohaematology (ICMR), 13th floor, new multistoried building, K.E.M Hospital campus, Parel, Mumbai, 400012, India
| | - Purvi Panchal
- Department of Cytogenetics, National Institute of Immunohaematology (ICMR), 13th floor, new multistoried building, K.E.M Hospital campus, Parel, Mumbai, 400012, India
| | - Jagdeeshwar Ghatanatti
- Department of Cytogenetics, National Institute of Immunohaematology (ICMR), 13th floor, new multistoried building, K.E.M Hospital campus, Parel, Mumbai, 400012, India
| | - Jitendra Suralkar
- Department of Cytogenetics, National Institute of Immunohaematology (ICMR), 13th floor, new multistoried building, K.E.M Hospital campus, Parel, Mumbai, 400012, India
| | - Anjali Shah
- Department of Cytogenetics, National Institute of Immunohaematology (ICMR), 13th floor, new multistoried building, K.E.M Hospital campus, Parel, Mumbai, 400012, India
| | - Babu Rao Vundinti
- Department of Cytogenetics, National Institute of Immunohaematology (ICMR), 13th floor, new multistoried building, K.E.M Hospital campus, Parel, Mumbai, 400012, India.
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17
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Karim S, Saharti S, Alganmi N, Mirza Z, Alfares A, Turkistany S, Al-Attas M, Noureldin H, Al Sakkaf K, Abusamra H, Al-Qahtani M, Abuzenadah A. Two Novel Homozygous HPS6 Mutations (Double Mutant) Identified by Whole-Exome Sequencing in a Saudi Consanguineous Family Suspected for Oculocutaneous Albinism. Life (Basel) 2021; 12:life12010014. [PMID: 35054407 PMCID: PMC8779141 DOI: 10.3390/life12010014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Revised: 12/11/2021] [Accepted: 12/13/2021] [Indexed: 11/28/2022] Open
Abstract
Background: Oculocutaneous albinism (OCA) is an autosomal recessive disorder of low or missing pigmentation in the eyes, hair, and skin. Multiple types of OCA, including Hermansky-Pudlak syndrome 6 (HPS6), are distinguished by their genetic cause and pigmentation pattern. HPS6 is characterized by OCA, nose bleeding due to platelet dysfunction, and lysosome storage defect. To date, 25 disease-associated mutations have been reported in the HPS6 gene. Methods: DNA was extracted from proband, and whole-exome sequencing (WES) was performed using the Illumina NovaSeq platform. Bioinformatic analysis was done with a custom-designed filter pipeline to detect the causative variant. We did Sanger sequencing to confirm the candidate variant and segregation analysis, and protein-based structural analysis to evaluate the functional impact of variants. Result: Proband-based WES identified two novel homozygous mutations in HPS6 (double mutation, c.1136C>A and c.1789delG) in an OCA suspect. Sanger sequencing confirmed the WES results. Although no platelet and/or lysosome storage defect was detected in the patient or family, an oculocutaneous albinism diagnosis was established based on the HPS6 mutations. Structural analysis revealed the transformation of abnormalities at protein level for both nonsense and frameshift mutations in HPS6. Conclusion: To the best of our knowledge, the double mutation in HPS6 (p.Ser379Ter and p.Ala597GlnfsTer16) represents novel pathogenic variants, not described previously, which we report for the first time in the Saudi family. In silico analyses showed a significant impact on protein structure. WES should be used to identify HPS6 and/or other disease-associated genetic variants in Saudi Arabia, particularly in consanguineous families.
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Affiliation(s)
- Sajjad Karim
- Center of Excellence in Genomic Medicine Research, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (M.A.-Q.); (A.A.)
- Department of Medical Lab Technology, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah 21589, Saudi Arabia;
- Correspondence: ; Tel.: +966-557581741
| | - Samah Saharti
- Department of Pathology, Faculty of Medicine, King Abdulaziz University, Jeddah 21589, Saudi Arabia;
| | - Nofe Alganmi
- Computer Science Department, Faculty of Computing and Information Technology, King Abdulaziz University, Jeddah 21589, Saudi Arabia;
| | - Zeenat Mirza
- Department of Medical Lab Technology, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah 21589, Saudi Arabia;
- King Fahd Medical Research Center, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Ahmed Alfares
- Division of Genetics, Department of Pediatrics, King Abdulaziz Medical City, Riyadh 11426, Saudi Arabia;
| | - Shereen Turkistany
- Center of Innovation in Personalized Medicine, King Abdulaziz University, Jeddah 21589, Saudi Arabia;
| | - Manal Al-Attas
- Roya Specialized Medical Laboratories, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (M.A.-A.); (H.N.); (K.A.S.); (H.A.)
| | - Hend Noureldin
- Roya Specialized Medical Laboratories, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (M.A.-A.); (H.N.); (K.A.S.); (H.A.)
| | - Khadega Al Sakkaf
- Roya Specialized Medical Laboratories, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (M.A.-A.); (H.N.); (K.A.S.); (H.A.)
| | - Heba Abusamra
- Roya Specialized Medical Laboratories, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (M.A.-A.); (H.N.); (K.A.S.); (H.A.)
| | - Mohammed Al-Qahtani
- Center of Excellence in Genomic Medicine Research, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (M.A.-Q.); (A.A.)
| | - Adel Abuzenadah
- Center of Excellence in Genomic Medicine Research, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (M.A.-Q.); (A.A.)
- Department of Medical Lab Technology, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah 21589, Saudi Arabia;
- King Fahd Medical Research Center, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah 21589, Saudi Arabia
- Roya Specialized Medical Laboratories, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (M.A.-A.); (H.N.); (K.A.S.); (H.A.)
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18
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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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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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Fernández A, Hayashi M, Garrido G, Montero A, Guardia A, Suzuki T, Montoliu L. Genetics of non-syndromic and syndromic oculocutaneous albinism in human and mouse. Pigment Cell Melanoma Res 2021; 34:786-799. [PMID: 33960688 DOI: 10.1111/pcmr.12982] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 04/21/2021] [Accepted: 04/26/2021] [Indexed: 01/12/2023]
Abstract
Oculocutaneous albinism (OCA) is the most frequent presentation of albinism, a heterogeneous rare genetic condition generally associated with variable alterations in pigmentation and with a profound visual impairment. There are non-syndromic and syndromic types of OCA, depending on whether the gene product affected impairs essentially the function of melanosomes or, in addition, that of other lysosome-related organelles (LROs), respectively. Syndromic OCA can be more severe and associated with additional systemic consequences, beyond pigmentation and vision alterations. In addition to OCA, albinism can also be presented without obvious skin and hair pigmentation alterations, in ocular albinism (OA), and a related genetic condition known as foveal hypoplasia, optic nerve decussation defects, and anterior segment dysgenesis (FHONDA). In this review, we will focus only in the genetics of skin pigmentation in OCA, both in human and mouse, updating our current knowledge on this subject.
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Affiliation(s)
- Almudena Fernández
- Department of Molecular and Cellular Biology, National Centre for Biotechnology (CNB-CSIC), Madrid, Spain.,CIBERER-ISCIII, Madrid, Spain
| | - Masahiro Hayashi
- Department of Dermatology, Yamagata University Faculty of Medicine, Yamagata, Japan
| | - Gema Garrido
- Department of Molecular and Cellular Biology, National Centre for Biotechnology (CNB-CSIC), Madrid, Spain.,CIBERER-ISCIII, Madrid, Spain
| | - Andrea Montero
- Department of Molecular and Cellular Biology, National Centre for Biotechnology (CNB-CSIC), Madrid, Spain.,CIBERER-ISCIII, Madrid, Spain
| | - Ana Guardia
- Department of Molecular and Cellular Biology, National Centre for Biotechnology (CNB-CSIC), Madrid, Spain.,CIBERER-ISCIII, Madrid, Spain
| | - Tamio Suzuki
- Department of Dermatology, Yamagata University Faculty of Medicine, Yamagata, Japan
| | - Lluis Montoliu
- Department of Molecular and Cellular Biology, National Centre for Biotechnology (CNB-CSIC), Madrid, Spain.,CIBERER-ISCIII, Madrid, Spain
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21
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Kessel L, Kjer B, Lei U, Duno M, Grønskov K. Genotype-phenotype associations in Danish patients with ocular and oculocutaneous albinism. Ophthalmic Genet 2021; 42:230-238. [PMID: 33612058 DOI: 10.1080/13816810.2021.1881979] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
BACKGROUND The study aimed to describe genotype-phenotype associations in patients with oculocutaneous and ocular-only albinism and to evaluate a set of diagnostic criteria proposed recently by Kruijt et al. MATERIALS AND METHODS Genotype-phenotype associations in patients with a clinical diagnosis of albinism were studied based on imaging of hair and ocular features (nystagmus, iris color and translucency, fundus pigmentation and foveal development) and self-evaluated skin type. Patients were sub-grouped based on genetic findings. RESULTS Patients with biallelic variants in TYR (n = 29), OCA2 (n = 22), other albinism genes (n = 13) or monoallelic variants in GPR143 (n = 13) were included as were 15 patients with a pure clinical diagnosis but no genetic findings. In descending order the most common findings were: foveal hypoplasia (any hypoplasia 95.2%, severe 88.0%), nystagmus (93.5%), iris translucency (any translucency 80.2%, moderate to severe 31.5%), misrouting on VEP (80.0%): fundus hypopigmentation (any hypopigmentation: 75.8%, severe 30.1%), fair skin type (73.8%), blue irides (62.0%), blonde hair (57.5%), and unpigmented eye lashes (39.1%). There were no phenotypic differences between the different genetic subgroups of albinism but patients with a pathogenic haplotype in TYR in combination with a classic variant had less iris translucency than patients with two classic variants in TYR. CONCLUSIONS Ocular developmental features were the most common findings whereas phenotypic features related to pigmentation were less common findings but there were no genotype-phenotype correlations. All patients with a genetically confirmed diagnosis of albinism fulfilled the diagnostic criteria by Kruijt irrespective of genetic subtype.
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Affiliation(s)
- Line Kessel
- Department of Ophthalmology, Rigshospitalet-Kennedy Center, Denmark.,Department of Clinical Medicine, University of Copenhagen, Copenhagen Denmark
| | - Birgit Kjer
- Department of Ophthalmology, Rigshospitalet-Kennedy Center, Denmark
| | - Ulrikke Lei
- Department of Clinical Medicine, University of Copenhagen, Copenhagen Denmark.,Department of Dermatology and Allergy, Herlev and Gentofte Hospital, Denmark
| | - Morten Duno
- Department of Clinical Genetics, Rigshospitalet-Kennedy Center, Denmark
| | - Karen Grønskov
- Department of Clinical Genetics, Rigshospitalet-Kennedy Center, Denmark
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22
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Current and emerging treatments for albinism. Surv Ophthalmol 2020; 66:362-377. [PMID: 33129801 DOI: 10.1016/j.survophthal.2020.10.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Revised: 10/07/2020] [Accepted: 10/21/2020] [Indexed: 12/24/2022]
Abstract
Albinism is a group of rare inherited disorders arising from impairment of melanin biosynthesis. The reduction of melanin synthesis leads to hypopigmentation of the skin and eyes. A wide range of ophthalmic manifestations arise from albinism, including reduction of visual acuity, nystagmus, strabismus, iris translucency, foveal hypoplasia, fundus hypopigmentation, and abnormal decussation of retinal ganglion cell axons at the optic chiasm. Currently, albinism is incurable, and treatment aims either surgically or pharmacologically to optimize vision and protect the skin; however, novel therapies that aim to directly address the molecular errors of albinism, such as l-dihydroxyphenylalanine and nitisinone, are being developed and have entered human trials though with limited success. Experimental gene-based strategies for editing the genetic errors in albinism have also met early success in animal models. The emergence of these new therapeutic modalities represents a new era in the management of albinism. We focus on the known genetic subtypes, clinical assessment, and existing and emerging therapeutic options for the nonsyndromic forms of albinism.
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23
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Okamura K, Suzuki T. Current landscape of Oculocutaneous Albinism in Japan. Pigment Cell Melanoma Res 2020; 34:190-203. [PMID: 32969595 DOI: 10.1111/pcmr.12927] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 09/05/2020] [Accepted: 09/10/2020] [Indexed: 12/16/2022]
Abstract
Oculocutaneous albinism (OCA), which is roughly divided into non-syndromic and syndromic OCA, is a group of autosomal recessive disorders caused by mutations in genes associated with pigmentation. Patients with OCA have hypopigmentation and ocular manifestations such as photophobia, amblyopia, and nystagmus. Hermansky-Pudlak syndrome (HPS), the most common syndromic OCA, is characterized by the additional features of a bleeding tendency and other critical systemic comorbidities such as pulmonary fibrosis and immunodeficiency. NGS-based gene analyses have identified several new causative genes for OCA and have detected rare subtypes of OCA with high accuracy including Japanese patients. In our survey of 190 Japanese OCA patients/families, OCA4 is the most common subtype (25.3%) followed by OCA1 (20.0%), HPS1 (14.7%), and OCA2 (8.4%). Similar to the A481T variant in OCA2, which is associated with a mild form of OCA2 and skin color variation, the c.-492_489delAATG variant located in the promoter region of SLC45A2 has been uniquely identified in Japanese patients with a mild form of OCA4. Further, rare OCA subtypes, including OCA3, HPS2, HPS3, HPS4, HPS5, HPS6, and HPS9, have also been identified in Japanese patients. The clinical characteristics and underlying molecular mechanisms of each subtype of OCA are concisely summarized in this review.
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Affiliation(s)
- Ken Okamura
- Department of Dermatology, Faculty of Medicine, Yamagata University, Yamagata, Japan
| | - Tamio Suzuki
- Department of Dermatology, Faculty of Medicine, Yamagata University, Yamagata, Japan
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24
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Bibi N, Ullah A, Darwesh L, Khan W, Khan T, Ullah K, Khan B, Ahmad W. Identification and Computational Analysis of Novel TYR and SLC45A2 Gene Mutations in Pakistani Families With Identical Non-syndromic Oculocutaneous Albinism. Front Genet 2020; 11:749. [PMID: 32849781 PMCID: PMC7385404 DOI: 10.3389/fgene.2020.00749] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 06/23/2020] [Indexed: 12/19/2022] Open
Abstract
Non-syndromic oculocutaneous albinism (nsOCA) is an inherited disorder of melanin biosynthesis with autosomal recessive mode of inheritance, presenting either hypopigmented or depigmented skin, hair, and eyes. It is genetically heterogeneous with seven loci (OCA1–OCA7) reported to date. In the present study, we have reported three consanguineous families (A, B, C) presenting identical nsOCA phenotypes. Sanger sequencing revealed a novel [NM_000372.5: c.826 T > C, p.(Cys276Arg)] and a recurrent variant [NM_000372.5: c.832C > T, p.(Arg278∗)] in tyrosinase (TYR) in families A and B, respectively. Microsatellite marker-based homozygosity mapping linked family C to OCA4. Sequence analysis identified a novel insertion variant (NM_016180.5: c.1331_1332insA) in the SLC45A2. Further, in silico mutagenesis and dynamic simulation approaches revealed that a novel Cys276Arg variant abolished the cysteine bridge and might contribute toward decreased stability of the TYR protein. Our study expands the mutation spectrum of the TYR and SLC45A2 genes and emphasizes that molecular investigations are essential for accurate disease diagnosis.
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Affiliation(s)
- Nousheen Bibi
- Department of Bioinformatics, Shaheed Benazir Bhutto Women University, Peshawar, Pakistan
| | - Asmat Ullah
- Department of Biochemistry, Quaid-i-Azam University, Islamabad, Pakistan.,Department of Molecular Biology, Shaheed Zulfiqar Ali Bhutto Medical University, Islamabad, Pakistan
| | - Lubna Darwesh
- Department of Biochemistry, Hazara University, Mansehra, Pakistan
| | - Waqas Khan
- Department of Biochemistry, Hazara University, Mansehra, Pakistan
| | - Tanzeela Khan
- Department of Bioinformatics, Shaheed Benazir Bhutto Women University, Peshawar, Pakistan
| | - Kalim Ullah
- Department of Zoology, Kohat University of Science and Technology, Kohat, Pakistan
| | - Bushra Khan
- Department of Biochemistry, Abdul Wali Khan University Mardan, Mardan, Pakistan
| | - Wasim Ahmad
- Department of Biochemistry, Quaid-i-Azam University, Islamabad, Pakistan
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25
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Schidlowski L, Liebert F, Iankilevich PG, Rebellato PRO, Rocha RA, Almeida NAP, Jain A, Wu Y, Itan Y, Rosati R, Prando C. Non-syndromic Oculocutaneous Albinism: Novel Genetic Variants and Clinical Follow Up of a Brazilian Pediatric Cohort. Front Genet 2020; 11:397. [PMID: 32411182 PMCID: PMC7198815 DOI: 10.3389/fgene.2020.00397] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Accepted: 03/30/2020] [Indexed: 12/11/2022] Open
Abstract
Oculocutaneous albinism (OCA) is a genetic disorder characterized by skin, hair, and eye hypopigmentation due to a reduction or absence of melanin. Clinical manifestations include vision problems and a high susceptibility to skin cancer. In its non-syndromic form, OCA is associated with six genes and one chromosomal region. Because OCA subtypes are not always clinically distinguishable, molecular analysis has become an important tool for classifying types of OCA, which facilitates genetic counseling and can guide the development of new therapies. We studied eight Brazilian individuals aged 1.5–18 years old with clinical diagnosis of OCA. Assessment of ophthalmologic characteristics showed results consistent with albinism, including reduced visual acuity, nystagmus, and loss of stereoscopic vision. We also observed the appearance of the strabismus and changes in static refraction over a 2-year period. Dermatologic evaluation showed that no participants had preneoplastic skin lesions, despite half of the participants reporting insufficient knowledge about skin care in albinism. Whole-exome and Sanger sequencing revealed eight different mutations: six in the TYR gene and two in the SLC45A2 gene, of which one was novel and two were described in a population study but were not previously associated with the OCA phenotype. We performed two ophthalmological evaluations, 2 years apart; and one dermatological evaluation. To the best of our knowledge, this is the first study to perform clinical follow-up and genetic analysis of a Brazilian cohort with albinism. Here, we report three new OCA causing mutations.
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Affiliation(s)
- Laire Schidlowski
- Instituto de Pesquisa Pelé Pequeno Príncipe, Curitiba, Brazil.,Faculdades Pequeno Príncipe, Curitiba, Brazil
| | - Fernando Liebert
- Instituto de Pesquisa Pelé Pequeno Príncipe, Curitiba, Brazil.,Faculdades Pequeno Príncipe, Curitiba, Brazil
| | | | | | | | | | - Aayushee Jain
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Yiming Wu
- The Charles Bronfman Institute for Personalized Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Yuval Itan
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, United States.,The Charles Bronfman Institute for Personalized Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Roberto Rosati
- Instituto de Pesquisa Pelé Pequeno Príncipe, Curitiba, Brazil.,Faculdades Pequeno Príncipe, Curitiba, Brazil
| | - Carolina Prando
- Instituto de Pesquisa Pelé Pequeno Príncipe, Curitiba, Brazil.,Faculdades Pequeno Príncipe, Curitiba, Brazil.,Hospital Pequeno Príncipe, Curitiba, Brazil
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26
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Yousaf S, Sethna S, Chaudhary MA, Shaikh RS, Riazuddin S, Ahmed ZM. Molecular characterization of SLC24A5 variants and evaluation of Nitisinone treatment efficacy in a zebrafish model of OCA6. Pigment Cell Melanoma Res 2020; 33:556-565. [PMID: 32274888 DOI: 10.1111/pcmr.12879] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 02/26/2020] [Accepted: 03/30/2020] [Indexed: 02/06/2023]
Abstract
Skin pigmentation is a highly heterogeneous trait with diverse consequences worldwide. SLC24A5, encoding a potent K+ -dependent Na+ /Ca2+ exchanger, is among the known color-coding genes that participate in melanogenesis by maintaining pH in melanosomes. Deficient SLC24A5 activity results in oculocutaneous albinism (OCA) type 6 in humans. In this study, by utilizing a exome sequencing (ES) approach, we identified two new variants [p. (Gly110Arg) and p. (IIe189Ilefs*1)] of SLC24A5 cosegregating with the OCA phenotype, including nystagmus, strabismus, foveal hypoplasia, albinotic fundus, and vision impairment, in three large consanguineous Pakistani families. Both of these variants failed to rescue the pigmentation in zebrafish slc24a5 morphants, confirming the pathogenic effects of the variants. We also phenotypically characterized a commercially available zebrafish mutant line (slc24a5ko ) that harbors a nonsense (p.Tyr208*) allele of slc24a5. Similar to morphants, homozygous slc24a5ko mutants had significantly reduced melanin content and pigmentation. Next, we used these slc24a5ko zebrafish mutants to test the efficacy of nitisinone, a compound known to increase ocular and fur pigmentation in OCA1 (TYR) mutant mice. Treatment of slc24a5ko mutant zebrafish embryos with varying doses of nitisinone did not improve melanin production and pigmentation, suggesting that treatment with nitisinone is unlikely to be therapeutic in OCA6 patients.
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Affiliation(s)
- Sairah Yousaf
- Department of Otorhinolaryngology Head and Neck Surgery, School of Medicine, University of Maryland, Baltimore, MD, USA.,Institute of Molecular Biology & Biotechnology, Bahauddin Zakariya University, Multan, Pakistan
| | - Saumil Sethna
- Department of Otorhinolaryngology Head and Neck Surgery, School of Medicine, University of Maryland, Baltimore, MD, USA
| | | | - Rehan S Shaikh
- Institute of Molecular Biology & Biotechnology, Bahauddin Zakariya University, Multan, Pakistan
| | - Saima Riazuddin
- Department of Otorhinolaryngology Head and Neck Surgery, School of Medicine, University of Maryland, Baltimore, MD, USA.,Department of Biochemistry and Molecular Biology, School of Medicine, University of Maryland, Baltimore, MD, USA
| | - Zubair M Ahmed
- Department of Otorhinolaryngology Head and Neck Surgery, School of Medicine, University of Maryland, Baltimore, MD, USA.,Department of Biochemistry and Molecular Biology, School of Medicine, University of Maryland, Baltimore, MD, USA.,Department of Ophthalmology and Visual Sciences, School of Medicine, University of Maryland, Baltimore, MD, USA
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27
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Plateau Grass and Greenhouse Flower? Distinct Genetic Basis of Closely Related Toad Tadpoles Respectively Adapted to High Altitude and Karst Caves. Genes (Basel) 2020; 11:genes11020123. [PMID: 31979140 PMCID: PMC7073644 DOI: 10.3390/genes11020123] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Revised: 01/03/2020] [Accepted: 01/19/2020] [Indexed: 12/21/2022] Open
Abstract
Genetic adaptation to extremes is a fascinating topic. Nevertheless, few studies have explored the genetic adaptation of closely related species respectively inhabiting distinct extremes. With deep transcriptome sequencing, we attempt to detect the genetic architectures of tadpoles of five closely related toad species adapted to the Tibetan Plateau, middle-altitude mountains and karst caves. Molecular evolution analyses indicated that not only the number of fast evolving genes (FEGs), but also the functioning coverage of FEGs, increased with elevation. Enrichment analyses correspondingly revealed that the highland species had most of the FEGs involved in high-elevation adaptation, for example, amino acid substitutions of XRCC6 in its binding domains might improve the capacity of DNA repair of the toad. Yet, few FEGs and positively selected genes (PSGs) involved in high-elevation adaptation were identified in the cave species, and none of which potentially contributed to cave adaptation. Accordingly, it is speculated that in the closely related toad tadpoles, genetic selection pressures increased with elevation, and cave adaptation was most likely derived from other factors (e.g., gene loss, pseudogenization or deletion), which could not be detected by our analyses. The findings supply a foundation for understanding the genetic adaptations of amphibians inhabiting extremes.
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28
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Bataille P, Michaud V, Robert MP, Bekel L, Leclerc‐Mercier S, Harroche A, Célérier C, Lasseaux E, Borgel D, Bremond‐Gignac D, Bodemer C, Arveiler B, Hadj‐Rabia S. Clinical variability and probable founder effect in oculocutaneous albinism type 7. Clin Genet 2019; 97:527-528. [DOI: 10.1111/cge.13655] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 09/26/2019] [Accepted: 09/30/2019] [Indexed: 11/28/2022]
Affiliation(s)
- Pauline Bataille
- Reference Centre for Genodermatoses and Rare Skin Disease (MAGEC) and Department of DermatologyFilière Maladies Rares Dermatologiques (FIMARAD), ERN‐Skin Hôpital Necker‐Enfants Malades, Université de Paris‐Centre Paris France
| | - Vincent Michaud
- Molecular Genetics LaboratoryCHU de Bordeaux Bordeaux France
| | - Matthieu P. Robert
- Reference Centre for Rare Ocular Diseases (OPHTARA) and Department of Ophthalmology, Hôpital Necker‐Enfants Malades, APHPUniversité de Paris‐Centre Paris France
| | - Lilia Bekel
- Reference Centre for Genodermatoses and Rare Skin Disease (MAGEC) and Department of DermatologyFilière Maladies Rares Dermatologiques (FIMARAD), ERN‐Skin Hôpital Necker‐Enfants Malades, Université de Paris‐Centre Paris France
| | | | - Annie Harroche
- Hematology, Hôpital Necker‐Enfants Malades, APHPUniversité de Paris‐Centre Paris France
| | - Charlotte Célérier
- Head&Neck Surgery, Hôpital Necker‐Enfants Malades, APHPUniversité de Paris‐Centre Paris France
| | | | - Delphine Borgel
- Hematology, Hôpital Necker‐Enfants Malades, APHPUniversité de Paris‐Centre Paris France
| | - Dominique Bremond‐Gignac
- Reference Centre for Rare Ocular Diseases (OPHTARA) and Department of Ophthalmology, Hôpital Necker‐Enfants Malades, APHPUniversité de Paris‐Centre Paris France
| | - Christine Bodemer
- Reference Centre for Genodermatoses and Rare Skin Disease (MAGEC) and Department of DermatologyFilière Maladies Rares Dermatologiques (FIMARAD), ERN‐Skin Hôpital Necker‐Enfants Malades, Université de Paris‐Centre Paris France
| | - Benoit Arveiler
- Molecular Genetics LaboratoryCHU de Bordeaux Bordeaux France
- Unité INSERM U1211, Maladies RaresGénétique et Métabolisme Bordeaux France
| | - Smaïl Hadj‐Rabia
- Reference Centre for Genodermatoses and Rare Skin Disease (MAGEC) and Department of DermatologyFilière Maladies Rares Dermatologiques (FIMARAD), ERN‐Skin Hôpital Necker‐Enfants Malades, Université de Paris‐Centre Paris France
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29
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Albinism: epidemiology, genetics, cutaneous characterization, psychosocial factors. An Bras Dermatol 2019; 94:503-520. [PMID: 31777350 PMCID: PMC6857599 DOI: 10.1016/j.abd.2019.09.023] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2019] [Accepted: 09/09/2019] [Indexed: 11/20/2022] Open
Abstract
Oculocutaneous albinism is an autosomal recessive disease caused by the complete absence or decrease of melanin biosynthesis in melanocytes. Due to the reduction or absence of melanin, albinos are highly susceptible to the harmful effects of ultraviolet radiation and are at increased risk of actinic damage and skin cancer. In Brazil, as in other parts of the world, albinism remains a little known disorder, both in relation to epidemiological data and to phenotypic and genotypic variation. In several regions of the country, individuals with albinism have no access to resources or specialized medical care, and are often neglected and deprived of social inclusion. Brazil is a tropical country, with a high incidence of solar radiation during the year nationwide. Consequently, actinic damage and skin cancer occur early and have a high incidence in this population, often leading to premature death. Skin monitoring of these patients and immediate therapeutic interventions have a positive impact in reducing the morbidity and mortality associated with this condition. Health education is important to inform albinos and their families, the general population, educators, medical professionals, and public agencies about the particularities of this genetic condition. The aim of this article is to present a review of the epidemiological, clinical, genetic, and psychosocial characteristics of albinism, with a focus in skin changes caused by this rare pigmentation disorder.
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30
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Peng F, Zhu G, Hysi PG, Eller RJ, Chen Y, Li Y, Hamer MA, Zeng C, Hopkins RL, Jacobus CL, Wallace PL, Uitterlinden AG, Ikram MA, Nijsten T, Duffy DL, Medland SE, Spector TD, Walsh S, Martin NG, Liu F, Kayser M. Genome-Wide Association Studies Identify Multiple Genetic Loci Influencing Eyebrow Color Variation in Europeans. J Invest Dermatol 2019; 139:1601-1605. [DOI: 10.1016/j.jid.2018.12.029] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Revised: 11/29/2018] [Accepted: 12/12/2018] [Indexed: 11/30/2022]
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31
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Zhong Z, Gu L, Zheng X, Ma N, Wu Z, Duan J, Zhang J, Chen J. Comprehensive analysis of spectral distribution of a large cohort of Chinese patients with non-syndromic oculocutaneous albinism facilitates genetic diagnosis. Pigment Cell Melanoma Res 2019; 32:672-686. [PMID: 31077556 PMCID: PMC6852118 DOI: 10.1111/pcmr.12790] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 03/31/2019] [Accepted: 05/05/2019] [Indexed: 12/25/2022]
Abstract
Non-syndromic oculocutaneous albinism (nsOCA) is a group of genetically heterogeneous autosomal recessive disorders with complete lack or decrease pigmentation in skin, hair, and eyes. TYR, OCA2, TYRP1, SLC45A2, SLC24A5, and LRMDA were reported to cause OCA1-4 and OCA6-7, respectively. By sequencing all the known nsOCA genes in 114 unrelated Chinese nsOCA patients combined with In silico analyses, splicing assay, and classification of variants according to the standards and guidelines of American College of Medical Genetics and Genomics, we detected seventy-one different OCA-causing variants separately in TYR, OCA2, SLC45A2, and SLC24A5, including thirty-one novel variants (13 in TYR, 11 in OCA2, and 7 in SLC45A2). This study shows that OCA1 is the most common (75/114) and OCA2 ranks the second most common (16/114) in Chinese. 99 patients of our cohort were caused by variants of all the known nsOCA genes. Cutaneous phenotypes of OCA1, OCA2, and OCA4 patients were shown in this study. The second OCA6 case in China was identified here. These data expand the spectrum of OCA variants as well phenotype and facilitate clinical implement of Chinese OCA patients.
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Affiliation(s)
- Zilin Zhong
- Department of Pediatrics of Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China.,Department of Medical Genetics, Tongji University School of Medicine, Shanghai, China.,Department of Regenerative Medicine, Tongji University School of Medicine, Shanghai, China
| | - Li Gu
- Department of Pediatrics of Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China
| | - Xiujie Zheng
- Department of Pediatrics of Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China.,Department of Medical Genetics, Tongji University School of Medicine, Shanghai, China
| | - Nengjun Ma
- Department of Pediatrics of Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China.,Department of Medical Genetics, Tongji University School of Medicine, Shanghai, China
| | - Zehua Wu
- Department of Pediatrics of Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China.,Department of Medical Genetics, Tongji University School of Medicine, Shanghai, China
| | - Juan Duan
- Department of Auxiliary Reproductive, Jiujiang Maternal and Child Health Hospital, Jiujiang, China
| | - Jun Zhang
- Department of Regenerative Medicine, Tongji University School of Medicine, Shanghai, China
| | - Jianjun Chen
- Department of Pediatrics of Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China.,Department of Medical Genetics, Tongji University School of Medicine, Shanghai, China.,Department of Regenerative Medicine, Tongji University School of Medicine, Shanghai, China
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32
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Abstract
Human skin and hair color are visible traits that can vary dramatically within and across ethnic populations. The genetic makeup of these traits-including polymorphisms in the enzymes and signaling proteins involved in melanogenesis, and the vital role of ion transport mechanisms operating during the maturation and distribution of the melanosome-has provided new insights into the regulation of pigmentation. A large number of novel loci involved in the process have been recently discovered through four large-scale genome-wide association studies in Europeans, two large genetic studies of skin color in Africans, one study in Latin Americans, and functional testing in animal models. The responsible polymorphisms within these pigmentation genes appear at different population frequencies, can be used as ancestry-informative markers, and provide insight into the evolutionary selective forces that have acted to create this human diversity.
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Affiliation(s)
- William J Pavan
- Genetic Disease Research Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland 20892, USA;
| | - Richard A Sturm
- Dermatology Research Centre, The University of Queensland Diamantina Institute, The University of Queensland, Brisbane, Queensland 4102, Australia;
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Herriges JC, Dugan SL, Lamb AN. Clinical and molecular cytogenetic characterization of a novel 10q interstitial deletion: a case report and review of the literature. Mol Cytogenet 2019; 12:20. [PMID: 31131026 PMCID: PMC6525357 DOI: 10.1186/s13039-019-0430-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Accepted: 04/16/2019] [Indexed: 12/17/2022] Open
Abstract
Background There are only ten reported cases of interstitial deletions involving cytogenetic bands 10q21.3q22.2 in the literature. Of the ten patients with overlapping 10q21.3q22.2 interstitial deletions, only nine have been characterized by chromosomal microarray analysis. Here, we report a two-and-a-half-year-old patient with a de novo 10.2-Mb deletion that extends from 10q21.3 to 10q22.3 and contains 92 protein coding genes. Case presentation The patient is the product of a 37-week dizygotic twin pregnancy and presented with global developmental delay, hypotonia, feeding difficulties, short stature, poor weight gain, scaphocephaly, retrognathia, hypoplasia of the optic nerves/chiasms, a distinctive facial gestalt, as well as additional minor dysmorphic features. The deletion identified in our patient is the second largest reported interstitial deletion involving the 10q21.3q22.2 region. Our patient presents with the generalized features observed in 10q21.3q22.2 deletion patients and also presents with several novel findings including scaphocephaly, hypoplasia of the optic nerves and chiasms, and a very distinctive facial gestalt. Conclusions Based on a literature review, we identify a commonly deleted region and suggest that KAT6B is a critical gene within the 10q21.3q22.2 region. However, a review of the reported overlapping deletions also suggests that there are additional critical genes contributing to the clinical presentation of these patients. Electronic supplementary material The online version of this article (10.1186/s13039-019-0430-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- John C Herriges
- 1Department of Pathology, University of Utah, Salt Lake City, UT USA.,2ARUP Laboratories, 500 Chipeta Way, Salt Lake City, UT 84108 USA
| | - Sarah L Dugan
- 3Department of Pediatric Medical Genetics, University of Utah, Salt Lake City, USA
| | - Allen N Lamb
- 1Department of Pathology, University of Utah, Salt Lake City, UT USA.,2ARUP Laboratories, 500 Chipeta Way, Salt Lake City, UT 84108 USA
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Onojafe IF, Megan LH, Melch MG, Aderemi JO, Alur RP, Abu-Asab MS, Chan CC, Bernardini IM, Albert JS, Cogliati T, Adams DR, Brooks BP. Minimal Efficacy of Nitisinone Treatment in a Novel Mouse Model of Oculocutaneous Albinism, Type 3. Invest Ophthalmol Vis Sci 2019; 59:4945-4952. [PMID: 30347088 PMCID: PMC6181301 DOI: 10.1167/iovs.16-20293] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Purpose Oral nitisinone has been shown to increase fur and ocular pigmentation in a mouse model of oculocutaneous albinism (OCA) due to hypomorphic mutations in tyrosinase (TYR), OCA1B. This study determines if nitisinone can improve ocular and/or fur pigmentation in a mouse model of OCA type 3 (OCA3), caused by mutation of the tyrosinase-related protein 1 (Tyrp1) gene. Methods Mice homozygous for a null allele in the Tyrp1 gene (C57BL/6J-Tyrp1 b-J/J) were treated with 8 mg/kg nitisinone or vehicle every other day by oral gavage. Changes in fur and ocular melanin pigmentation were monitored. Mature ocular melanosome number and size were quantified in pigmented ocular structures by electron microscopy. Results C57BL/6J-Tyrp1 b-J/J mice carry a novel c.403T>A; 404delG mutation in Tyrp1, predicted to result in premature truncation of the TYRP1 protein. Nitisinone treatment resulted in an approximately 7-fold increase in plasma tyrosine concentrations without overt toxicity. After 1 month of treatment, no change in the color of fur or pigmented ocular structures was observed. The distribution of melanosome cross-sectional area was unchanged in ocular tissues. There was no significant difference in the number of pigmented melanosomes in the RPE/choroid of nitisinone-treated and control groups. However, there was a significant difference in the number of pigmented melanosomes in the iris. Conclusions Treatment of a mouse model of OCA3 with oral nitisinone did not have a favorable clinical effect on melanin production and minimally affected the number of pigmented melanosomes in the iris stroma. As such, treatment of OCA3 patients with nitisinone is unlikely to be therapeutic.
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Affiliation(s)
- Ighovie F Onojafe
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Lucyanne H Megan
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Madeline G Melch
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Joseph O Aderemi
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Ramakrishna P Alur
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Mones S Abu-Asab
- Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Chi-Chao Chan
- Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Isa M Bernardini
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Jessica S Albert
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Tiziana Cogliati
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - David R Adams
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Brian P Brooks
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
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35
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Comprehensive Review of the Genetics of Albinism. JOURNAL OF VISUAL IMPAIRMENT & BLINDNESS 2018. [DOI: 10.1177/0145482x1811200604] [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
Introduction It is important to understand albinism, since it is a disorder associated with visual impairment, predisposition to malignant melanomas, and social stigma. The main objective of this article is to review the genetics and biologic mechanisms of the non-syndromic albinism subtypes and to describe associated clinical manifestations. We also discuss research on its treatments. Methods A review of the published literature on albinism subtypes was performed, spanning basic laboratory research, published case reports, and experiences of people with albinism. Results Clear progress has been made in comprehending the causes of albinism; research has shed light on the complexity of the disorder and has led to the molecular classification of subtypes. Discussion Despite the increase in knowledge with regards to albinism, gaps still exist. It is important to continue the pursuit of unraveling the mechanism of the disorder and to monitor the frequency of the subtypes worldwide in order to aid in the development of treatments. Furthermore, disseminating knowledge of albinism is crucial for future progress. Implications for practitioners Albinism is a disorder characterized by hypopigmentation of the hair, skin, and eyes, with accompanying ocular abnormalities that remain relatively stable throughout life. The disorder is defined by a spectrum of pigmentation where albinism is more evident among individuals of dark complexion than their lighter-pigmented peers. Patients with albinism require protection against sun exposure and special resources to address visual impairments. When albinism patients are diagnosed and properly accommodated, they generally report a positive quality of life.
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Morice-Picard F, Taïeb C, Marti A, Gliksohn A, Bennani M, Bodemer C, Ezzedine K. Burden of albinism: development and validation of a burden assessment tool. Orphanet J Rare Dis 2018; 13:162. [PMID: 30227882 PMCID: PMC6145119 DOI: 10.1186/s13023-018-0894-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2018] [Accepted: 08/20/2018] [Indexed: 11/22/2022] Open
Abstract
Background Albinism comprises a group of autosomal recessive diseases that are characterized by poor vision and a variable hypopigmentation phenotype. A comprehensive literature review showed that no tool can assess the burden experienced by individuals who present with albinism, although such a tool is needed and would be beneficial for clinicians and patients alike. Method The questionnaire was devised using standardized methodology for developing and validating questionnaires on the quality of life of subjects according to the following chronological structure: conceptual phase, development phase, and then validation phase. A multidisciplinary working group was assembled, including experts on questionnaire design and development, dermatologists specializing in care for patients with albinism, and representatives of the Genespoir association. Results Based on an initial verbatim report, the workgroup compiled a list of items that were transcribed and reformulated into questions. During the validation phase, principal component analysis (PCA) was conducted on the 24 items, which allowed the questionnaire to be reduced to 20 questions [Q]. The standardized regression coefficients were all greater than 0.5 for their corresponding factors. Based on their normalized regression coefficients, each group of questions was linked to one of the following four dimensions, with each dimension consisting of at least three questions: “Live with” (8 Q), “Daily life” (3 Q), “Resignation” (3 Q), and “Fear of the future” (6 Q). All dimensions correlated well with the overall BoA score. Cronbach’s α was 0.92 for the entire BoA scale, confirming excellent internal coherence. Intradimensional coherences all demonstrated excellent reliability (α > 0.65). The BoA questionnaire was highly correlated with the SF12, RSES and DLQI validated questionnaires. This outcome confirmed the external validity. Conclusion This questionnaire represents the first specific assessment tool for evaluating the burden of albinism. It is easy to use and relatively quick to complete, which will allow the burden to be evaluated over time with a reproducible questionnaire. To ensure that this questionnaire can be used by as many people as possible, cultural and linguistic validation in US English was conducted with the original French version. Electronic supplementary material The online version of this article (10.1186/s13023-018-0894-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | - Charles Taïeb
- FIMARAD, Hôpital Necker-Enfants Malades, APHP, Paris, France.
| | | | | | | | - Christine Bodemer
- MAGEC, CHU Necker-Enfants Malades, APHP, Paris, France.,Annimatrice, FIMARAD, Hôpital Necker-Enfants Malades, APHP, Paris, France
| | - Khaled Ezzedine
- EA EpiDermE, UPE-Université Paris-Est, Créteil, France.,CHU H Mondor, APHP, Créteil, France
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McCafferty BK, Holleschau AM, Connett JE, Summers CG. Visual Development During the Second Decade of Life in Albinism. J Pediatr Ophthalmol Strabismus 2018; 55:254-259. [PMID: 29809263 DOI: 10.3928/01913913-20180327-02] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Accepted: 09/28/2017] [Indexed: 11/20/2022]
Abstract
PURPOSE To evaluate change in best corrected visual acuity (BCVA) during the second decade of life and the effects of albinism type and extraocular muscle surgery on BCVA in children with albinism. METHODS In this retrospective longitudinal study, 41 patients with albinism with clinic visits recording binocular BCVA at least once between the ages of 10 and 13 years (visit A) and again between the ages of 17 and 20 years (visit B) were included. Type of albinism, age at each visit, and interval eye muscle surgeries were recorded for each patient. RESULTS Forty (98%) patients showed BCVA improvement or stability between visits A and B. There was no significant effect of interval extraocular muscle surgery on BCVA. Those carrying either a clinically presumed or moleculary confirmed diagnosis of oculocutaneous albinism types 1B and 2 had the best visual outcomes, consistent with previous studies. CONCLUSIONS In the majority of patients with albinism, significant improvement in BCVA occurs during the second decade of life. Extraocular muscle surgery was not a significant factor in BCVA improvement in albinism. Overall, the assessments support the finding of improvement of visual acuity in children with albinism at earlier ages and provide new information beneficial in predicting visual outcomes in the second decade of life. [J Pediatr Ophthalmol Strabismus. 2018;55(4):254-259.].
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Lin TF, Gerth-Kahlert C, Hanson JVM, Straumann D, Huang MYY. Spontaneous Nystagmus in the Dark in an Infantile Nystagmus Patient May Represent Negative Optokinetic Afternystagmus. Front Neurol 2018; 9:151. [PMID: 29593643 PMCID: PMC5861190 DOI: 10.3389/fneur.2018.00151] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 02/28/2018] [Indexed: 11/13/2022] Open
Abstract
Abnormal projection of the optic nerves to the wrong cerebral hemisphere transforms the optokinetic system from its usual negative feedback loop to a positive feedback loop with characteristic ocular motor instabilities including directional reversal of the optokinetic nystagmus (OKN) and spontaneous nystagmus, which are common features of infantile nystagmus syndrome (INS). Visual input plays a critical role in INS linked to an underlying optic nerve misprojection such as that often seen in albinism. However, spontaneous nystagmus often continues in darkness, making the visual, sensory-driven etiology questionable. We propose that sensorimotor adaptation during the constant nystagmus of patients in the light could account for continuing nystagmus in the dark. The OKN is a stereotyped reflexive eye movement in response to motion in the surround and serves to stabilize the visual image on the retina, allowing high resolution vision. Robust negative optokinetic afternystagmus (negative OKAN), referring to the continuous nystagmus in the dark with opposite beating direction of the preceding OKN, has been identified in various non-foveated animals. In humans, a robust afternystagmus in the same direction as previous smooth-pursuit movements (the eye's continuous tracking and foveation of a moving target) induced by visual stimuli has been known to commonly mask negative OKAN. Some INS patients are often associated with ocular hypopigmentation, foveal hypoplasia, and compromised smooth pursuit. We identified an INS case with negative OKAN in the dark, in contrast to the positive afternystagmus in healthy subjects. We hypothesize that spontaneous nystagmus in the dark in INS patients may be attributable to sensory adaptation in the optokinetic system after a sustained period of spontaneous nystagmus with directional visual input in light.
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Affiliation(s)
- Ting-Feng Lin
- Department of Neurology, University Hospital Zurich, University of Zurich, Zurich, Switzerland.,Neuroscience Center Zurich (ZNZ), University of Zurich and ETH Zurich, Zurich, Switzerland
| | | | - James V M Hanson
- Department of Ophthalmology, University Hospital Zurich, Zurich, Switzerland.,Neuroimmunology and Multiple Sclerosis Research, Clinic for Neurology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Dominik Straumann
- Department of Neurology, University Hospital Zurich, University of Zurich, Zurich, Switzerland.,Neuroscience Center Zurich (ZNZ), University of Zurich and ETH Zurich, Zurich, Switzerland
| | - Melody Ying-Yu Huang
- Department of Neurology, University Hospital Zurich, University of Zurich, Zurich, Switzerland.,Neuroscience Center Zurich (ZNZ), University of Zurich and ETH Zurich, Zurich, Switzerland
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Lasseaux E, Plaisant C, Michaud V, Pennamen P, Trimouille A, Gaston L, Monfermé S, Lacombe D, Rooryck C, Morice-Picard F, Arveiler B. Molecular characterization of a series of 990 index patients with albinism. Pigment Cell Melanoma Res 2018; 31:466-474. [PMID: 29345414 DOI: 10.1111/pcmr.12688] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 01/07/2018] [Indexed: 01/11/2023]
Abstract
Albinism is a clinically and genetically heterogeneous disease characterized by variable degrees of hypopigmentation and by nystagmus, foveal hypoplasia, and chiasmatic misrouting of the optic nerves. The wide phenotypic heterogeneity impedes the establishment of phenotype-genotype correlations. To obtain a precise diagnosis, we screened the 19 known albinism genes in 990 index patients using targeted next-generation sequencing (NGS) and high-resolution comparative genomic hybridization. A molecular diagnosis was obtained in 72.32% of patients. A total of 243 new pathogenic variants were identified. Intragenic rearrangements represented 10.8% of all pathogenic alleles. NGS panel analysis allowed establishing a diagnosis for the rarest forms of the disease, which could not be diagnosed otherwise. Because of the clinical overlap between the different forms of the disease, diagnosis nowadays clearly relies on molecular grounds.
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Affiliation(s)
- Eulalie Lasseaux
- Service de Génétique Médicale, CHU de Bordeaux, Bordeaux, France
| | - Claudio Plaisant
- Service de Génétique Médicale, CHU de Bordeaux, Bordeaux, France
| | - Vincent Michaud
- Service de Génétique Médicale, CHU de Bordeaux, Bordeaux, France
| | - Perrine Pennamen
- Service de Génétique Médicale, CHU de Bordeaux, Bordeaux, France.,INSERM U1211, Maladies Rares, Génétique et Métabolisme, Université de Bordeaux, Bordeaux, France
| | - Aurelien Trimouille
- Service de Génétique Médicale, CHU de Bordeaux, Bordeaux, France.,INSERM U1211, Maladies Rares, Génétique et Métabolisme, Université de Bordeaux, Bordeaux, France
| | - Laetitia Gaston
- Service de Génétique Médicale, CHU de Bordeaux, Bordeaux, France
| | | | - Didier Lacombe
- Service de Génétique Médicale, CHU de Bordeaux, Bordeaux, France.,INSERM U1211, Maladies Rares, Génétique et Métabolisme, Université de Bordeaux, Bordeaux, France
| | - Caroline Rooryck
- Service de Génétique Médicale, CHU de Bordeaux, Bordeaux, France.,INSERM U1211, Maladies Rares, Génétique et Métabolisme, Université de Bordeaux, Bordeaux, France
| | | | - Benoît Arveiler
- Service de Génétique Médicale, CHU de Bordeaux, Bordeaux, France.,INSERM U1211, Maladies Rares, Génétique et Métabolisme, Université de Bordeaux, Bordeaux, France
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Dolinska MB, Kus NJ, Farney SK, Wingfield PT, Brooks BP, Sergeev YV. Oculocutaneous albinism type 1: link between mutations, tyrosinase conformational stability, and enzymatic activity. Pigment Cell Melanoma Res 2017; 30:41-52. [PMID: 27775880 DOI: 10.1111/pcmr.12546] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Accepted: 10/13/2016] [Indexed: 12/19/2022]
Abstract
Oculocutaneous albinism type 1 (OCA1) is an autosomal recessive disorder caused by mutations in the tyrosinase gene. Two subtypes of OCA1 have been described: severe OCA1A with complete absence of tyrosinase activity and less severe OCA1B with residual tyrosinase activity. Here, we characterize the recombinant human tyrosinase intramelanosomal domain and mutant variants, which mimic genetic changes in both subtypes of OCA1 patients. Proteins were prepared using site-directed mutagenesis, expressed in insect larvae, purified by chromatography, and characterized by enzymatic activities, tryptophan fluorescence, and Gibbs free energy changes. The OCA1A mutants showed very low protein expression and protein yield and are enzymatically inactive. Mutants mimicking OCA1B were biochemically similar to the wild type, but exhibited lower specific activities and protein stabilities. The results are consistent with clinical data, which indicates that OCA1A mutations inactivate tyrosinase and result in severe phenotype, while OCA1B mutations partially inactivate tyrosinase and result in OCA1B albinism.
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Affiliation(s)
- Monika B Dolinska
- National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Nicole J Kus
- National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - S Katie Farney
- National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Paul T Wingfield
- National Institute of Artritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Brian P Brooks
- National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Yuri V Sergeev
- National Eye Institute, National Institutes of Health, Bethesda, MD, USA
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Marti A, Lasseaux E, Ezzedine K, Léauté-Labrèze C, Boralevi F, Paya C, Coste V, Deroissart V, Arveiler B, Taieb A, Morice-Picard F. Lessons of a day hospital: Comprehensive assessment of patients with albinism in a European setting. Pigment Cell Melanoma Res 2017; 31:318-329. [DOI: 10.1111/pcmr.12651] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2017] [Accepted: 09/22/2017] [Indexed: 12/24/2022]
Affiliation(s)
- Aurélie Marti
- Paediatric Dermatology Unit; National Reference Center for Rare Skin Disorders; Hôpital Pellegrin-Enfants; Bordeaux University Hospitals; Bordeaux France
| | | | - Khaled Ezzedine
- Department of Dermatology; AP-HP; Hôpital Henri-Mondor; Créteil France
| | - Christine Léauté-Labrèze
- Paediatric Dermatology Unit; National Reference Center for Rare Skin Disorders; Hôpital Pellegrin-Enfants; Bordeaux University Hospitals; Bordeaux France
| | - Franck Boralevi
- Paediatric Dermatology Unit; National Reference Center for Rare Skin Disorders; Hôpital Pellegrin-Enfants; Bordeaux University Hospitals; Bordeaux France
| | - Clément Paya
- Ophthalmology Department; CHU de Bordeaux; Bordeaux France
| | | | - Vincent Deroissart
- Institute of Public Health; Epidemiology and Development “ISPED”; Bordeaux University; Bordeaux France
| | - Benoit Arveiler
- Molecular Genetics Laboratory; CHU de Bordeaux; Bordeaux France
- Unité INSERM U1211; Maladies Rares: Génétique et Métabolisme; Bordeaux France
| | - Alain Taieb
- Paediatric Dermatology Unit; National Reference Center for Rare Skin Disorders; Hôpital Pellegrin-Enfants; Bordeaux University Hospitals; Bordeaux France
- Unité INSERM 1035; BMGIC; Immuno-dermatology ATIP-AVENIR; University of Bordeaux; Bordeaux France
| | - Fanny Morice-Picard
- Paediatric Dermatology Unit; National Reference Center for Rare Skin Disorders; Hôpital Pellegrin-Enfants; Bordeaux University Hospitals; Bordeaux France
- Molecular Genetics Laboratory; CHU de Bordeaux; Bordeaux France
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Two Variants in SLC24A5 Are Associated with "Tiger-Eye" Iris Pigmentation in Puerto Rican Paso Fino Horses. G3-GENES GENOMES GENETICS 2017; 7:2799-2806. [PMID: 28655738 PMCID: PMC5555483 DOI: 10.1534/g3.117.043786] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A unique eye color, called tiger-eye, segregates in the Puerto Rican Paso Fino (PRPF) horse breed and is characterized by a bright yellow, amber, or orange iris. Pedigree analysis identified a simple autosomal recessive mode of inheritance for this trait. A genome-wide association study (GWAS) with 24 individuals identified a locus on ECA 1 reaching genome-wide significance (Pcorrected = 1.32 × 10−5). This ECA1 locus harbors the candidate gene, Solute Carrier Family 24 (Sodium/Potassium/Calcium Exchanger), Member 5 (SLC24A5), with known roles in pigmentation in humans, mice, and zebrafish. Humans with compound heterozygous mutations in SLC24A5 have oculocutaneous albinism (OCA) type 6 (OCA6), which is characterized by dilute skin, hair, and eye pigmentation, as well as ocular anomalies. Twenty tiger-eye horses were homozygous for a nonsynonymous mutation in exon 2 (p.Phe91Tyr) of SLC24A5 (called here Tiger-eye 1), which is predicted to be deleterious to protein function. Additionally, eight of the remaining 12 tiger-eye horses heterozygous for the p.Phe91Tyr variant were also heterozygous for a 628 bp deletion encompassing all of exon 7 of SLC24A5 (c.875-340_1081+82del), which we will call here the Tiger-eye 2 allele. None of the 122 brown-eyed horses were homozygous for either tiger-eye-associated allele or were compound heterozygotes. Further, neither variant was detected in 196 horses from four related breeds not known to have the tiger-eye phenotype. Here, we propose that two mutations in SLC24A5 affect iris pigmentation in tiger-eye PRPF horses. Further, unlike OCA6 in humans, the Tiger-eye 1 mutation in its homozygous state or as a compound heterozygote (Tiger-eye 1/Tiger-eye 2) does not appear to cause ocular anomalies or a change in coat color in the PRPF horse.
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Wang C, Brancusi F, Valivullah ZM, Anderson MG, Cunningham D, Hedberg-Buenz A, Power B, Simeonov D, Gahl WA, Zein WM, Adams DR, Brooks B. A novel iris transillumination grading scale allowing flexible assessment with quantitative image analysis and visual matching. Ophthalmic Genet 2017; 39:41-45. [PMID: 28742462 DOI: 10.1080/13816810.2017.1342134] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
PURPOSE To develop a sensitive scale of iris transillumination suitable for clinical and research use, with the capability of either quantitative analysis or visual matching of images. METHODS Iris transillumination photographic images were used from 70 study subjects with ocular or oculocutaneous albinism. Subjects represented a broad range of ocular pigmentation. A subset of images was subjected to image analysis and ranking by both expert and nonexpert reviewers. Quantitative ordering of images was compared with ordering by visual inspection. Images were binned to establish an 8-point scale. Ranking consistency was evaluated using the Kendall rank correlation coefficient (Kendall's tau). Visual ranking results were assessed using Kendall's coefficient of concordance (Kendall's W) analysis. RESULTS There was a high degree of correlation among the image analysis, expert-based and non-expert-based image rankings. Pairwise comparisons of the quantitative ranking with each reviewer generated an average Kendall's tau of 0.83 ± 0.04 (SD). Inter-rater correlation was also high with Kendall's W of 0.96, 0.95, and 0.95 for nonexpert, expert, and all reviewers, respectively. CONCLUSIONS The current standard for assessing iris transillumination is expert assessment of clinical exam findings. We adapted an image-analysis technique to generate quantitative transillumination values. Quantitative ranking was shown to be highly similar to a ranking produced by both expert and nonexpert reviewers. This finding suggests that the image characteristics used to quantify iris transillumination do not require expert interpretation. Inter-rater rankings were also highly similar, suggesting that varied methods of transillumination ranking are robust in terms of producing reproducible results.
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Affiliation(s)
- Chen Wang
- a Section on Human Biochemical Genetics , National Human Genome Research Institute, National Institutes of Health , Bethesda , Maryland , USA
| | - Flavia Brancusi
- a Section on Human Biochemical Genetics , National Human Genome Research Institute, National Institutes of Health , Bethesda , Maryland , USA
| | - Zaheer M Valivullah
- b Undiagnosed Diseases Program, NIH Common Fund, Office of the Director , National Human Genome Research Institute, National Institutes of Health , Bethesda , Maryland , USA
| | - Michael G Anderson
- c Department of Molecular Physiology and Biophysics , University of Iowa , Iowa City , Iowa , USA.,d Center for the Prevention and Treatment of Visual Loss , Iowa City Veterans Affairs (VA) Health Care System , Iowa City , Iowa , USA
| | - Denise Cunningham
- e National Eye Institute , National Institutes of Health , Bethesda , Maryland , USA
| | - Adam Hedberg-Buenz
- c Department of Molecular Physiology and Biophysics , University of Iowa , Iowa City , Iowa , USA.,d Center for the Prevention and Treatment of Visual Loss , Iowa City Veterans Affairs (VA) Health Care System , Iowa City , Iowa , USA
| | - Bradley Power
- a Section on Human Biochemical Genetics , National Human Genome Research Institute, National Institutes of Health , Bethesda , Maryland , USA
| | - Dimitre Simeonov
- f Department of Human Biochemical Genetics , University of California, San Francisco , San Francisco , California , USA
| | - William A Gahl
- a Section on Human Biochemical Genetics , National Human Genome Research Institute, National Institutes of Health , Bethesda , Maryland , USA
| | - Wadih M Zein
- e National Eye Institute , National Institutes of Health , Bethesda , Maryland , USA
| | - David R Adams
- a Section on Human Biochemical Genetics , National Human Genome Research Institute, National Institutes of Health , Bethesda , Maryland , USA
| | - Brian Brooks
- e National Eye Institute , National Institutes of Health , Bethesda , Maryland , USA
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Fábos B, Farkas K, Tóth L, Sulák A, Tripolszki K, Tihanyi M, Németh R, Vas K, Csoma Z, Kemény L, Széll M, Nagy N. Delineating the genetic heterogeneity of OCA in Hungarian patients. Eur J Med Res 2017. [PMID: 28629449 PMCID: PMC5477306 DOI: 10.1186/s40001-017-0262-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND Oculocutaneous albinism (OCA) is a clinically and genetically heterogenic group of pigmentation abnormalities characterized by variable hair, skin, and ocular hypopigmentation. Six known genes and a locus on human chromosome 4q24 have been implicated in the etiology of isolated OCA forms (OCA 1-7). METHODS The most frequent OCA types among Caucasians are OCA1, OCA2, and OCA4. We aimed to investigate genes responsible for the development of these OCA forms in Hungarian OCA patients (n = 13). Mutation screening and polymorphism analysis were performed by direct sequencing on TYR, OCA2, SLC45A2 genes. RESULTS Although the clinical features of the investigated Hungarian OCA patients were identical, the molecular genetic data suggested OCA1 subtype in eight cases and OCA4 subtype in two cases. The molecular diagnosis was not clearly identifiable in three cases. In four patients, two different heterozygous known pathogenic or predicted to be pathogenic mutations were present. Seven patients had only one pathogenic mutation, which was associated with non-pathogenic variants in six cases. In two patients no pathogenic mutation was identified. CONCLUSIONS Our results suggest that the concomitant screening of the non-pathogenic variants-which alone do not cause the development of OCA, but might have clinical significance in association with a pathogenic variant-is important. Our results also show significant variation in the disease spectrum compared to other populations. These data also confirm that the concomitant analysis of OCA genes is critical, providing new insights to the phenotypic diversity of OCA and expanding the mutation spectrum of OCA genes in Hungarian patients.
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Affiliation(s)
- Beáta Fábos
- Mór Kaposi Teaching Hospital of the Somogy County, Kaposvár, Hungary
| | - Katalin Farkas
- MTA-SZTE Dermatological Research Group, University of Szeged, Szeged, Hungary
| | - Lola Tóth
- Department of Medical Genetics, University of Szeged, 4 Somogyi Bela Street, 6720, Szeged, Hungary
| | - Adrienn Sulák
- Department of Medical Genetics, University of Szeged, 4 Somogyi Bela Street, 6720, Szeged, Hungary
| | - Kornélia Tripolszki
- Department of Medical Genetics, University of Szeged, 4 Somogyi Bela Street, 6720, Szeged, Hungary
| | - Mariann Tihanyi
- Genetic Laboratory, Hospital of Zala County, Zalaegerszeg, Hungary
| | - Réka Németh
- Department of Dermatology and Allergology, University of Szeged, Szeged, Hungary
| | - Krisztina Vas
- Department of Dermatology and Allergology, University of Szeged, Szeged, Hungary
| | - Zsanett Csoma
- Department of Dermatology and Allergology, University of Szeged, Szeged, Hungary
| | - Lajos Kemény
- MTA-SZTE Dermatological Research Group, University of Szeged, Szeged, Hungary.,Department of Dermatology and Allergology, University of Szeged, Szeged, Hungary
| | - Márta Széll
- MTA-SZTE Dermatological Research Group, University of Szeged, Szeged, Hungary.,Department of Medical Genetics, University of Szeged, 4 Somogyi Bela Street, 6720, Szeged, Hungary
| | - Nikoletta Nagy
- MTA-SZTE Dermatological Research Group, University of Szeged, Szeged, Hungary. .,Department of Medical Genetics, University of Szeged, 4 Somogyi Bela Street, 6720, Szeged, Hungary. .,Department of Dermatology and Allergology, University of Szeged, Szeged, Hungary.
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Lei TY, Wang HT, Li F, Cui YQ, Fu F, Li R, Liao C. Application of high resolution SNP arrays in patients with congenital oral clefts in south China. J Genet 2017; 95:801-809. [PMID: 27994178 DOI: 10.1007/s12041-016-0696-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Chromosome microarray analysis (CMA) has proven to be a powerful tool in postnatal patients with intellectual disabilities. However, the diagnostic capability of CMA in patients with congenital oral clefts remain mysterious. Here, we present our clinical experience in implementing whole-genome high-resolution SNP arrays to investigate 33 patients with syndromic and nonsyndromic oral clefts in whom standard karyotyping analyses showed normal karyotypes. We aim to identify the genomic aetiology and candidate genes in patients with congenital oral clefts. CMA revealed copy number variants (CNVs) in every patient, which ranged from 2 to 9 per sample. The size of detected CNVs varied from 100 to 3.2 Mb. In 33 patients, we identified six clinically significant CNVs. The incidence of clinically significant CNVs was 18.2% (6/33). Three of these six CNVs were detected in patients with nonsyndromic clefts, including one who presented with isolated cleft lip with cleft palate (CLP) and two with cleft palate only (CPO). The remaining three CNVs were detected in patients with syndromic clefts. However, no CNV was detected in patients with cleft lip only (CLO). The six clinically significant CNVs were as follows: 8p23.1 microduplication (198 kb); 10q22.2-q22.3 microdeletion (1766 kb); 18q12.3 microduplication (638 kb); 20p12.1 microdeletion (184 kb); 6q26 microdeletion (389 kb); and 22q11.21-q11.23 microdeletion (3163 kb). In addition, two novel candidate genes for oral clefts, KAT6B and MACROD2, were putatively identified. We also found a CNV of unknown clinical significance with a detection rate of 3.0% (1/33). Our results further support the notion that CNVs significantly contributed to the genetic aetiology of oral clefts and emphasize the efficacy of whole-genome high-resolution SNP arrays to detect novel candidate genes in patients with syndromic and nonsyndromic clefts.
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Affiliation(s)
- Ting-Ying Lei
- Department of Prenatal Diagnostic Center Guangzhou Medical University, Guangdong, 510623, People's Republic of China.
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Li Y, Geng X, Bao L, Elaswad A, Huggins KW, Dunham R, Liu Z. A deletion in the Hermansky–Pudlak syndrome 4 (Hps4) gene appears to be responsible for albinism in channel catfish. Mol Genet Genomics 2017; 292:663-670. [DOI: 10.1007/s00438-017-1302-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 02/11/2017] [Indexed: 10/20/2022]
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47
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Clinical evaluation and molecular screening of a large consecutive series of albino patients. J Hum Genet 2016; 62:277-290. [PMID: 27734839 DOI: 10.1038/jhg.2016.123] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Revised: 09/08/2016] [Accepted: 09/10/2016] [Indexed: 12/26/2022]
Abstract
Oculocutaneous albinism (OCA) is characterized by hypopigmentation of the skin, hair and eye, and by ophthalmologic abnormalities caused by a deficiency in melanin biosynthesis. In this study we recruited 321 albino patients and screened them for the genes known to cause oculocutaneous albinism (OCA1-4 and OCA6) and ocular albinism (OA1). Our purpose was to detect mutations and genetic frequencies of the main causative genes, offering to albino patients an exhaustive diagnostic assessment within a multidisciplinary approach including ophthalmological, dermatological, audiological and genetic evaluations. We report 70 novel mutations and the frequencies of the major causative OCA genes that are as follows: TYR (44%), OCA2 (17%), TYRP1 (1%), SLC45A2 (7%) and SLC24A5 (<0.5%). An additional 5% of patients had GPR143 mutations. In 19% of cases, a second reliable mutation was not detected, whereas 7% of our patients remain still molecularly undiagnosed. This comprehensive study of a consecutive series of OCA/OA1 patients allowed us to perform a clinical evaluation of the different OCA forms.
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A cross-sectional examination of visual acuity by specific type of albinism. J AAPOS 2016; 20:419-424. [PMID: 27647118 DOI: 10.1016/j.jaapos.2016.06.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Revised: 06/07/2016] [Accepted: 06/10/2016] [Indexed: 11/22/2022]
Abstract
PURPOSE Reports of best-corrected visual acuity (BCVA) in albinism are often based on overlapping clinical phenotypes. BCVA in albinism has been shown to improve with age. This study reports a large cross-sectional investigation to determine whether BCVA differs by specific type of albinism when age-corrected. METHODS This retrospective review identified 170 individuals with a specific type of albinism identified by mutation(s) in a gene known to cause albinism (for OCA1, OCA2, and Hermansky-Pudlak syndrome ([HPS]) or a specific phenotype (white hair and no melanin pigment in OCA1A; pigmentary mosaicism in the obligate carriers for males with OA1). We recorded optotype binocular BCVA at final follow-up. Patients were age-grouped (2-5 years, 6-14 years, and ≥15 years) for comparison. RESULTS The greatest visual acuity deficit was found for OCA1A in all age groups. At age ≥15 years (n = 79), mean BCVA was 20/128 for OCA1A, 20/37 for OCA1B, 20/59 for OCA2, 20/63 for OA1, and 20/121 for HPS. Significant differences between BCVA at ≥15 years were found in the following: OCA1A vs OCA1B, OCA1A vs OCA2, OCA1A vs OA1, OCA1B vs HPS, OCA2 vs HPS, and OA1 vs HPS (P ≤ 0.02). CONCLUSIONS This study provides a large sample size and includes only those with a specific type of albinism. BCVA varies by albinism type, and there is overlap in BCVA, particularly in the younger age groups. For ages ≥15 years, there are significant differences in BCVA between several types of albinism.
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Richardson R, Tracey-White D, Webster A, Moosajee M. The zebrafish eye-a paradigm for investigating human ocular genetics. Eye (Lond) 2016; 31:68-86. [PMID: 27612182 DOI: 10.1038/eye.2016.198] [Citation(s) in RCA: 110] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Accepted: 06/17/2016] [Indexed: 01/13/2023] Open
Abstract
Although human epidemiological and genetic studies are essential to elucidate the aetiology of normal and aberrant ocular development, animal models have provided us with an understanding of the pathogenesis of multiple developmental ocular malformations. Zebrafish eye development displays in depth molecular complexity and stringent spatiotemporal regulation that incorporates developmental contributions of the surface ectoderm, neuroectoderm and head mesenchyme, similar to that seen in humans. For this reason, and due to its genetic tractability, external fertilisation, and early optical clarity, the zebrafish has become an invaluable vertebrate system to investigate human ocular development and disease. Recently, zebrafish have been at the leading edge of preclinical therapy development, with their amenability to genetic manipulation facilitating the generation of robust ocular disease models required for large-scale genetic and drug screening programmes. This review presents an overview of human and zebrafish ocular development, genetic methodologies employed for zebrafish mutagenesis, relevant models of ocular disease, and finally therapeutic approaches, which may have translational leads in the future.
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Affiliation(s)
- R Richardson
- Department of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, London, UK
| | - D Tracey-White
- Department of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, London, UK
| | - A Webster
- Department of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, London, UK.,NIHR Biomedical Research Centre for Ophthalmology, Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - M Moosajee
- Department of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, London, UK.,NIHR Biomedical Research Centre for Ophthalmology, Moorfields Eye Hospital NHS Foundation Trust, London, UK
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Kamaraj B, Purohit R. Mutational Analysis on Membrane Associated Transporter Protein (MATP) and Their Structural Consequences in Oculocutaeous Albinism Type 4 (OCA4)-A Molecular Dynamics Approach. J Cell Biochem 2016; 117:2608-19. [PMID: 27019209 DOI: 10.1002/jcb.25555] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Accepted: 03/24/2016] [Indexed: 12/11/2022]
Abstract
Oculocutaneous albinism type IV (OCA4) is an autosomal recessive inherited disorder which is characterized by reduced biosynthesis of melanin pigmentation in skin, hair, and eyes and caused by the genetic mutations in the membrane-associated transporter protein (MATP) encoded by SLC45A2 gene. The MATP protein consists of 530 amino acids which contains 12 putative transmembrane domains and plays an important role in pigmentation and probably functions as a membrane transporter in melanosomes. We scrutinized the most OCA4 disease-associated mutation and their structural consequences on SLC45A2 gene. To understand the atomic arrangement in 3D space, the native and mutant structures were modeled. Further the structural behavior of native and mutant MATP protein was investigated by molecular dynamics simulation (MDS) approach in explicit lipid and water background. We found Y317C as the most deleterious and disease-associated SNP on SLC45A2 gene. In MDS, mutations in MATP protein showed loss of stability and became more flexible, which alter its structural conformation and function. This phenomenon has indicated a significant role in inducing OCA4. Our study explored the understanding of molecular mechanism of MATP protein upon mutation at atomic level and further helps in the field of pharmacogenomics to develop a personalized medicine for OCA4 disorder. J. Cell. Biochem. 117: 2608-2619, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Balu Kamaraj
- Research Group PLASMANT, Department of Chemistry, University of Antwerp, Universiteitsplein 1, 2610, Wilrijk-Antwerp, Belgium
| | - Rituraj Purohit
- Department of Biotechnology, CSIR-Institute of Himalayan Bioresource Technology, Palampur, Himachal Pradesh, India.
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