Taylor, RL, Arno, G, Poulter, JA orcid.org/0000-0003-2048-5693 et al. (17 more authors) (2017) Association of Steroid 5α-Reductase Type 3 Congenital Disorder of Glycosylation With Early-Onset Retinal Dystrophy. JAMA Ophthalmology, 135 (4). pp. 339-347. ISSN 2168-6165
Abstract
Importance: Steroid 5α-reductase type 3 congenital disorder of glycosylation (SRD5A3-CDG) is a rare disorder of N-linked glycosylation. Its retinal phenotype is not well described but could be important for disease recognition because it appears to be a consistent primary presenting feature. Objective: To investigate a series of patients with the same mutation in the SRD5A3 gene and thereby characterize its retinal manifestations and other associated features. Design, Setting and Participants: Seven affected individuals from 4 unrelated families with early-onset retinal dystrophy as a primary manifestation underwent comprehensive ophthalmic assessment, including retinal imaging and electrodiagnostic testing. Developmental and systemic findings were also recorded. Molecular genetic approaches, including targeted next-generation sequencing, autozygosity mapping, and apex microarray, were tried to reach a diagnosis; all participants were mutation negative. Whole-exome sequencing or whole-genome sequencing was used to identify the causative variant. Biochemical profiling was conducted to confirm a CDG type I defect. Patient phenotype data were collected over the course of ophthalmic follow-up, spanning a period of 20 years, beginning March 20, 1997, through September 15, 2016. Main Outcomes and Measures: Detailed clinical phenotypes as well as genetic and biochemical results. Results: The cohort consisted of 7 participants (5 females and 2 males) whose mean (SD) age at the most recent examination was 17.1 (3.9) years and who were all of South Asian ethnicity. Whole-exome sequencing and whole-genome sequencing identified the same homozygous SRD5A3 c.57G>A, p.(Trp19Ter) variant as the underlying cause of early-onset retinal dystrophy in each family. Detailed ocular phenotyping identified early-onset (aged ≤3 years) visual loss (mean [SD] best-corrected visual acuity, +0.95 [0.34] logMAR [20/180 Snellen]), childhood-onset nyctalopia, myopia (mean [SD] refractive error, -6.71 [-4.22]), and nystagmus. Six of the 7 patients had learning difficulties and psychomotor delay. Fundus autofluorescence imaging and optical coherence tomographic scans were abnormal in all patients, and electrodiagnostic testing revealed rod and cone dysfunction in the 5 patients tested. Conclusions and Relevance: Mutations in the SRD5A3 gene may cause early-onset retinal dystrophy, a previously underdescribed feature of the SRD5A3-CDG disorder that is progressive and may lead to serious visual impairment. SRD5A3 and other glycosylation disorder genes should be considered as a cause of retinal dystrophy even when systemic features are mild. Further delineation of SRD5A3-associated eye phenotypes can help inform genetic counseling for prognostic estimation of visual loss and disease progression.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2017, American Medical Association. Reproduced in accordance with the publishers self-archiving policy. |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Medicine and Health (Leeds) > School of Medicine (Leeds) > Inst of Biomed & Clin Sciences (LIBACS) (Leeds) > Genetics (LIBACS) (Leeds) The University of Leeds > Faculty of Medicine and Health (Leeds) > Institute of Molecular Medicine (LIMM) (Leeds) > Section of Opthalmology and Neurosciences (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 14 Mar 2017 15:00 |
Last Modified: | 02 Mar 2018 01:38 |
Status: | Published |
Publisher: | American Medical Association (AMA) |
Identification Number: | 10.1001/jamaophthalmol.2017.0046 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:113605 |