1
|
Yi Z, Li S, Wang S, Xiao X, Sun W, Zhang Q. Clinical features and genetic spectrum of NMNAT1-associated retinal degeneration. Eye (Lond) 2022; 36:2279-2285. [PMID: 34837036 PMCID: PMC9674661 DOI: 10.1038/s41433-021-01853-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 10/14/2021] [Accepted: 11/10/2021] [Indexed: 11/09/2022] Open
Abstract
OBJECTIVES To systematically analyse the NMNAT1 variant spectrum and frequency, the associated phenotypic characteristics, and potential genotype-phenotype correlations based on our data and literature review. METHODS Biallelic potential pathogenic variants (PPV) in NMNAT1 were collected from our in-house exome sequencing data. Whole-genome sequencing was conducted subsequently for patients with only one heterozygous PPV detected in NMNAT1. The clinical data were reviewed and evaluated in detail. Furthermore, the literature was reviewed for reports of NMNAT1 variants and their associated phenotypes. RESULTS Eleven NMNAT1 variants, including two novel variants, were detected in 8 families from our cohort. All of the 9 available patients showed generalized tapetoretinal dystrophy at an early age (88.9% in the first decade), and disciform macular atrophy was identified in six patients from five unrelated families. Among a total of 125 patients from 8 families of our cohort and 91 families reported by the available literature, 92.9% patients showed onset of disease in the first year after birth, and 89.0% patients showed visual acuity of 0.05 or lower. All of the 39 patients with fundus photos available presented disciform macular atrophy with generalized tapetoretinal dystrophy. Most (54/80, 67.5%) of causative NMNAT1 variants were missense. The most frequent variants in Caucasian and Asian population are p.E257K and p.R237C, respectively. CONCLUSIONS Early-onset age, disciform macular atrophy with generalized tapetoretinal dystrophy, and poor visual acuity are the typical features of NMNAT1-associated retinal degeneration. Different variant hot spots of NMNAT1 were observed in different populations.
Collapse
Affiliation(s)
- Zhen Yi
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, 54 Xianlie Road, Guangzhou, 510060, China
| | - Shiqiang Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, 54 Xianlie Road, Guangzhou, 510060, China
| | - Siyu Wang
- Department of Ophthalmology, Li Chuan People's Hospital, Enshi, HuBei, 445400, China
| | - Xueshan Xiao
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, 54 Xianlie Road, Guangzhou, 510060, China
| | - Wenmin Sun
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, 54 Xianlie Road, Guangzhou, 510060, China
| | - Qingjiong Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, 54 Xianlie Road, Guangzhou, 510060, China.
| |
Collapse
|
2
|
Kayazawa T, Kuniyoshi K, Hatsukawa Y, Fujinami K, Yoshitake K, Tsunoda K, Shimojo H, Iwata T, Kusaka S. Clinical course of a Japanese girl with Leber congenital amaurosis associated with a novel nonsense pathogenic variant in NMNAT1: a case report and mini review. Ophthalmic Genet 2022; 43:400-408. [PMID: 35026968 DOI: 10.1080/13816810.2021.2023195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Leber congenital amaurosis (LCA), although rare, is one of the most severe forms of early-onset inherited retinal dystrophy (IRD). Here, we review the molecular genetics and phenotypic characteristics of patients with NMNAT1-associated IRD. The longitudinal clinical and molecular findings of a Japanese girl diagnosed with LCA associated with pathogenic variants in NMNAT1 c.648delG, (p.Trp216Ter*) and c.709C>T (p.Arg237Cys) have been described to highlight the salient clinical features of NMNAT1-associated IRD.
Collapse
Affiliation(s)
- Tomoyasu Kayazawa
- Department of Ophthalmology, Kindai University Faculty of Medicine, Osaka, Japan
| | - Kazuki Kuniyoshi
- Department of Ophthalmology, Kindai University Faculty of Medicine, Osaka, Japan
| | - Yoshikazu Hatsukawa
- Department of Ophthalmology, Osaka Women's and Children's Hospital, Osaka, Japan
| | - Kaoru Fujinami
- Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan.,Genetics, UCL Institute of Ophthalmology Associated with Moorfields Eye Hospital, London, UK.,Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan
| | - Kazutoshi Yoshitake
- Division of Molecular and Cellular Biology, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan.,Graduate School of Agricultural and Life Science, Faculty of Agriculture, The University of Tokyo, Tokyo, Japan
| | - Kazushige Tsunoda
- Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan
| | - Hiroshi Shimojo
- Department of Ophthalmology, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Takeshi Iwata
- Division of Molecular and Cellular Biology, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan
| | - Shunji Kusaka
- Department of Ophthalmology, Kindai University Faculty of Medicine, Osaka, Japan
| |
Collapse
|
3
|
Huang CH, Yang CM, Yang CH, Hou YC, Chen TC. Leber's Congenital Amaurosis: Current Concepts of Genotype-Phenotype Correlations. Genes (Basel) 2021; 12:genes12081261. [PMID: 34440435 PMCID: PMC8392113 DOI: 10.3390/genes12081261] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 08/15/2021] [Accepted: 08/18/2021] [Indexed: 12/26/2022] Open
Abstract
Leber’s congenital amaurosis (LCA), one of the most severe inherited retinal dystrophies, is typically associated with extremely early onset of visual loss, nystagmus, and amaurotic pupils, and is responsible for 20% of childhood blindness. With advances in molecular diagnostic technology, the knowledge about the genetic background of LCA has expanded widely, while disease-causing variants have been identified in 38 genes. Different pathogenetic mechanisms have been found among these varieties of genetic mutations, all of which result in the dysfunction or absence of their encoded proteins participating in the visual cycle. Hence, the clinical phenotypes also exhibit extensive heterogenicity, including the course of visual impairment, involvement of the macular area, alteration in retinal structure, and residual function of the diseased photoreceptor. By reviewing the clinical course, fundoscopic images, optical coherent tomography examination, and electroretinogram, genotype-phenotype correlations could be established for common genetic mutations in LCA, which would benefit the timing of the diagnosis and thus promote early intervention. Gene therapy is promising in the management of LCA, while several clinical trials are ongoing and preliminary success has been announced, focusing on RPE65 and other common disease-causing genes. This review provides an update on the genetics, clinical examination findings, and genotype-phenotype correlations in the most well-established causative genetic mutations of LCA.
Collapse
Affiliation(s)
- Chu-Hsuan Huang
- Department of Ophthalmology, Cathay General Hospital, Taipei 106, Taiwan; (C.-H.H.); (Y.-C.H.)
| | - Chung-May Yang
- Department of Ophthalmology, National Taiwan University Hospital, Taipei 100, Taiwan; (C.-M.Y.); (C.-H.Y.)
- Department of Ophthalmology, College of Medicine, National Taiwan University, Taipei 100, Taiwan
| | - Chang-Hao Yang
- Department of Ophthalmology, National Taiwan University Hospital, Taipei 100, Taiwan; (C.-M.Y.); (C.-H.Y.)
- Department of Ophthalmology, College of Medicine, National Taiwan University, Taipei 100, Taiwan
| | - Yu-Chih Hou
- Department of Ophthalmology, Cathay General Hospital, Taipei 106, Taiwan; (C.-H.H.); (Y.-C.H.)
| | - Ta-Ching Chen
- Department of Ophthalmology, National Taiwan University Hospital, Taipei 100, Taiwan; (C.-M.Y.); (C.-H.Y.)
- Correspondence: ; Tel.: +886-2-23123456
| |
Collapse
|
4
|
Kumaran N, Robson AG, Michaelides M. A NOVEL CASE SERIES OF NMNAT1-ASSOCIATED EARLY-ONSET RETINAL DYSTROPHY: EXTENDING THE PHENOTYPIC SPECTRUM. Retin Cases Brief Rep 2021; 15:139-144. [PMID: 30004997 DOI: 10.1097/icb.0000000000000754] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To report two siblings with NMNAT1-associated retinopathy presenting with a later onset and milder phenotype than previously described. METHODS Retrospective case series of two siblings. The authors describe two cases of early-onset retinal dystrophy caused by disease-causing NMNAT1 variants. Visual acuity, clinical examination, and retinal imaging including color fundus photography, spectral domain optical coherence tomography, and fundus autofluorescence were performed. Both cases underwent full-field and pattern electroretinography incorporating the International standards. RESULTS Two siblings were found to harbor the variants c.53A>G, p.(Asn18Ser) and c.769G>A, p.(Glu257Lys) in NMNAT1 after retinal dystrophy panel gene testing. Both had good visual acuity until the ages of 6 and 11 years, respectively, with subsequent gradual worsening into their twenties. At the ages of 10 and 16 years, respectively, electroretinograms indicated generalized rod and cone system dysfunction of moderate severity, with pattern electroretinography evidence of severe macular involvement. Repeat testing at the ages of 26 and 33 years revealed only mild worsening of rod photoreceptor function in both. CONCLUSION NMNAT1-associated retinopathy has previously only been described as a typical form of Leber congenital amaurosis, with poor visual acuity from birth associated with nystagmus, characteristic macular atrophy, and intraretinal pigmentation from birth. Here, we present two siblings with a novel, later onset, and far milder phenotype. We suggest that this may be due to the two missense NMNAT1 variants resulting in milder reduction of NMNAT1 enzymatic activity. These cases extend the phenotypic spectrum associated with NMNAT1 and further highlight the clinical heterogeneity associated with inherited retinal diseases.
Collapse
Affiliation(s)
- Neruban Kumaran
- UCL Institute of Ophthalmology, University College London, London, United Kingdom ; and
- Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom
| | - Anthony G Robson
- UCL Institute of Ophthalmology, University College London, London, United Kingdom ; and
- Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom
| | - Michel Michaelides
- UCL Institute of Ophthalmology, University College London, London, United Kingdom ; and
- Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom
| |
Collapse
|
5
|
NMNAT1-ASSOCIATED CONE-ROD DYSTROPHY: EVIDENCE FOR A SPECTRUM OF FOVEAL MALDEVELOPMENT. Retin Cases Brief Rep 2020; 16:385-392. [PMID: 32150116 DOI: 10.1097/icb.0000000000000992] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To describe in detail the phenotype of two siblings with biallelic NMNAT1 mutations. METHODS A 4-year-old male patient (P1) and his 7-year-old sister (P2), product of a nonconsanguineous union of Egyptian ancestry, underwent a comprehensive ophthalmic examination, retinal imaging with spectral domain optical coherence tomography and near infrared (NIR) fundus autofluorescence (FAF), and full-field electroretinograms (ERG). RESULTS Patients had blurred vision and nystagmus at ∼3 years of age. P2 was hyperopic (+6D). Visual acuity in P1 was 20/100 at age 3 and remained at ∼20/125 at age 4; P2 visual acuity was 20/70 at age 4 and declined to ∼20/200 at age 7. ERGs recorded in P1 showed relatively large rod-mediated responses but nearly undetectable cone signals. There was foveal/parafoveal depigmentation. Spectral domain optical coherence tomography showed hypoplastic foveas, a thin outer nuclear layer centrally but normal thickness beyond the vascular arcades. At the foveal center, cone outer segments were absent and the outer nuclear layer was further hyporreflective. The inner retina was mostly within normal limits. There was central depigmentation on near infrared fundus autofluorescence. Biallelic mutations were identified in NMNAT1: One was previously reported (c.769 G>A; pGlu257Lys), and the other one (c.245T>C; pVal82Ala) was novel. CONCLUSION NMNAT1 mutations cause a consistent phenotype characterized by early-onset, progressive, cone>rod retinawide dysfunction and predominantly central abnormalities ranging from a hypoplastic to an atrophic fovea, supporting a critical role for NMNAT1 in central retinal development and maintenance. Relatively preserved inner retina and detectable photoreceptors may become therapeutic targets.
Collapse
|