Ophthalmic Genetics最新文献

Background: Prior research has shown a positive association of pseudoexfoliative glaucoma (PXG) in patients with non-melanoma skin cancer (NMSC), likely due to an increase in ultraviolet exposure associated with both. However, the role of NMSC as a genetic risk factor for PXG has not been examined. Thus, the goal of this study is to utilize Mendelian randomization with genome-wide association studies to evaluate for genetic causality while controlling for environmental confounders.

Methods: We conducted a MR using the inverse variance weighted method (MR-IVW) as our primary analysis. Genomic data was sourced from GWASs for patients with NMSC (10,382 cases, 208,410 controls) and PXG (1,515 cases and 210,201 controls), originating from the FinnGen Biobank.

Results: Despite previous association of history of NMSC with occurrence of PXG, we found no evidence for a causal association between SNPs associated with NMSC and risk of PXG following MR analysis (MR-IVW, odds ratio (OR): 0.98, 95% CI: 0.85-1.14, P = 0.87).

Conclusion: Here, we found no evidence for a causal association between SNPs associated with NMSC and the risk of PXG following a MR analysis.

Background: Biallelic pathogenic variants in CDH23 can cause Usher syndrome type I (USH1), typically characterized by sensorineural hearing loss, variable vestibular areflexia, and a progressive form of rod-cone dystrophy. While missense variants in CDH23 can cause DFNB12 deafness, other variants can affect the cadherin 23 function, more severely causing Usher syndrome type I D. The main purpose of our study is to describe the genotypes and phenotypes of patients with mild retinitis pigmentosa (RP), including sector RP with two pathogenic variants in CDH23.

Materials and methods: Clinical examination included medical history, comprehensive ophthalmologic examination, and multimodal retinal imaging, and in case 1 and 2, full-field electroretinography (ERG). Genetic analysis was performed in all cases, and segregation testing of proband relatives was performed in case 1 and 3.

Results: Three unrelated cases presented with variable clinical phenotype for USH1 and were found to have two pathogenic variants in CDH23, with missense variant, c.5237 G > A: p.Arg1746Gln being common to all. All probands had mild to profound hearing loss. Case 1 and 3 had mild RP with mid peripheral and posterior pole sparing, while case 2 had sector RP. ERG results were consistent with the marked loss of retinal function in both eyes at the level of photoreceptor in case 1 and case 2, with normal peak time in the former.

Conclusion: Patients harbouring c.5237 G > A: p.Arg1746Gln variants in CDH23 can present with a mild phenotype including sector RP. This can aid in better genetic counselling and in prognostication.

Purpose: To report on a patient with spinocerebellar ataxia type 14 (SCA14) and macular dystrophy with identification of a novel PRPH2 variant.

Methods: Case report.

Results: A 63-year-old female with molecularly confirmed SCA14 presented with symmetric pigmentary disturbances in a perifoveal distribution resembling a pattern macular dystrophy. She had no history of using medications with recognized toxic macular effects. Subsequent genetic testing confirmed a novel heterozygous missense variant of unknown significance in PRPH2 (PRPH2: c.694 G>A, p.(Ala232Thr)).

Conclusions: To our knowledge, this is the first case of macular dystrophy identified in a patient with SCA14. While it is possible that the macular dystrophy observed in this patient might be an under-reported phenotype associated with SCA14, the pattern of macular changes is consistent with PRPH2-related disorders. The identified missense variant is predicted to be damaging by most in silico models, and the residue is highly conserved, adding support to a dual genetic diagnosis in this case.

Objective: To describe the inheritance pattern and clinical variability of primary congenital glaucoma (PCG) in a family with two affected siblings.

Materials and methods: Two sisters diagnosed at birth with bilateral PCG, whose father had bilateral PCG and mother had bilateral microphthalmus, were subjected to a familial genetic study and ophthalmologic follow-up including intraocular pressure (IOP) measurement, and collection of biometric and cup-to-disc ratio data.

Results: The inheritance pattern was autosomal recessive in compound heterozygosis. The sisters were found to be carriers of three pathogenic allele variants of the CYP1B1 gene: c.317C>A (p.Ala106Asp) and c.1345delG (p.Asp449MetfsTer8) in one patient (10 years) and c.1345delG (p.Asp449MetfsTer8) and c.202_209delCAGGCGGC (p.Gln68Serfs153Ter) in her older sister (12 years). Surgical histories included: three goniotomies and two Ahmed valves in each eye, and two trabeculectomies and a pupilloplasty in the right eye in the 10-year old; and one goniotomy, trabeculectomy and three Ahmed valves in each eye in the older sister. Currently, both sisters have a controlled intraocular pressure of 18-20 mmHg in both eyes. The father is blind in both eyes and carries two variants c.317C>A (p.Ala106Asp) and c.202_209delCAGGCGGC (p.Gln68Serfs153Ter). The mother with a single variant c.1345delG (p.Asp440MetfsTer8) has a prosthetic right eye and microphthalmus left eye.

Conclusions: The sisters were found to show two different allelic CYP1B1 variants (compound heterozygosis) with different repercussions on the clinical severity of PCG. These findings highlight the importance of genetic screening of affected families.

Background: Congenital cataract is a common cause of blindness. Genetic factors always play important role.

Material and methods: This study identified a novel missense variant (c.1412C>T (p.P471L)) in the EZR gene in a four-generation Chinese family with nuclear cataract by linkage analysis and whole-exome sequencing. A knockout study in zebrafish using transcription activator-like effector nucleases was carried out to gain insight into candidate gene function.

Results: Conservative and functional prediction suggests that the P-to-L substitution may impair the function of the human ezrin protein. Histology showed developmental delays in the ezrin-mutated zebrafish, manifesting as multilayered lens epithelial cells. Immunohistochemistry revealed abnormal proliferation patterns in mutant fish.

Conclusions: The study suggests that ezrin may be involved in the enucleation and differentiation of lens epithelial cells.

Background: Juvenile-onset open-angle glaucoma (JOAG) is a rare form of primary open-angle glaucoma (POAG) with an early age of onset before 40 years. Latent transforming growth factor-beta binding protein 2 (LTBP-2) is an extracellular matrix protein with a multi-domain structure and homology to fibrillins. LTBP2 gene variants have been associated with JOAG in a small number of patients. Herein, we report a novel missense variant in the LTBP2 gene in a Turkish family with JOAG.

Materials and methods: Blood samples were obtained from three siblings (a 20-year-old woman with JOAG, 26-year-old man with JOAG, and 15-year-old girl with posterior embryotoxon) for genetic analysis. Their father had moderate-severe POAG and the 24-year-old brother had JOAG. The mother and 32-year-old sister were healthy. Although the parents reported no consanguinity, they come from the same village.

Results: Clinical exome sequencing analysis of the two siblings with JOAG revealed a novel c.607C>T p.(R203C) (rs777450651) homozygous LTBP2 variant, while the variant was heterozygous in their 15-year-old sister. There were no mutations in the MYOC, CYP1B1, or FBN1 genes.

Conclusion: We documented a novel missense mutation in the LTBP2 gene leading to a severe form of JOAG with refractory IOP and progressive optic nerve damage, which seems to show autosomal recessive inheritance.

Background: GAPO syndrome is a rare autosomal recessive disorder characterized by the acronym of growth retardation, alopecia, pseudo-anodontia and progressive optic atrophy. While the genetic alteration of the ANTXR1 gene has been known for its cause, the full range of its clinical and genetic manifestations is not well explored due to the syndrome's extreme rarity.

Materials/methods: We report two children born to a non-consanguineous parent in India with classical features of GAPO syndrome. The whole exome sequencing analysis (WES) was performed in both siblings, and the parent's genetic and clinical status was determined. The identified variation was characterized in silico using homology-based protein modelling.

Results: In WES analysis, a homozygous ANTXR1 gene indel variant c. 151_152 + 2delAAGT (p.Lys51fs) was identified in both siblings. The parents were identified as the carriers of the ANTXR1 variant. Additionally, they also displayed mild GAPO-related facial and glaucomatous features. In silico analysis and homology-based ANTXR1 protein structure illustrate a frameshift and the subsequent premature truncation of the protein.

Conclusions: Our reports contribute to the comprehension of GAPO syndrome within the Indian context describing an ANTXR1 novel variant causing premature protein truncation. WES-based genetic testing can significantly aid in expertly diagnosing GAPO syndrome. In the present case scenario, a variable penetrance of ANTXR1 variation was acknowledged as the carrier parents also had a mild degree of GAPO-related features. Future reports that include parental clinical diagnosis can offer further insights in this context.

Background: Disease-causing variants in the KCNV2 gene are associated with "cone dystrophy with supernormal rod responses," a rare autosomal recessive retinal dystrophy. There is no previous report of hypomorphic variants in the disease.

Material and methods: Medical history, genetic testing, ocular examination, high-resolution retinal imaging including adaptive optics scanning light ophthalmoscopy (AOSLO), and functional assessments.

Results: A 16-year-old male with mild cone-rod dystrophy presented with reduced central vision and photophobia. Genetic testing showed two variants in KCNV2, c.614_617dupAGCG (p.207AlafsTer166) and c.854T>G (p.Met285Arg), the latter which was previously considered benign. Electrophysiological assessment revealed the pathognomic electroretinogram waveforms associated with KCNV2-retinopathy. Optical coherence tomography showed discrete focal ellipsoid zone disruption, while fundus autofluorescence was normal. Non-waveguiding cones corresponding to areas of loss of photoreceptor integrity were visible on adaptive optics scanning light ophthalmoscopy. Retinal sensitivity and fixation were relatively preserved, with a demonstrable deterioration after 14 months of follow-up.

Conclusions: We provide functional and structural evidence that the variant M285R is disease-causing if associated with a loss-of-function variant. To the best of our knowledge, this is the first hypomorphic allele reported in KCNV2.

Purpose: Occult macular dystrophy (OMD) is a cause of visual loss in young adults with a grossly normal fundus appearance. It is considered an autosomal dominant disorder, related to heterozygous pathogenic variants in the gene RP1L1. The purpose of this study is to report a biallelic form of the disease.

Results: A 29-year-old female had undergone neurological workup and ophthalmic examinations for transient visual loss in her left eye over the past two years but there was no definitive diagnosis. The best-corrected visual acuity was 20/30, 20/20. Indirect ophthalmoscopy with a 78D lens revealed subtle central retinal pigment epithelium mottling and optical coherence tomography confirmed subtle central thickening of the ellipsoid zone. Full-field electroretinography was normal, but pattern electroretinography showed decreased p50 responses. OMD was suspected. Retinal gene panel testing was significant only for a homozygous variant in RP1L1 (NM_178857.6: c.3571 G>T; p.Glu1191*). The parents and older brother were unavailable for segregation analysis. By history they did not have visual complaints other than a need for glasses.

Conclusions: This report presents the clinical and genetic findings of a biallelic form of OMD associated with a novel pathogenic variant in RP1L1. It would be of interest to carefully assess macular function in heterozygotes with this variant.

Purpose: The MEFV gene encodes pyrin, a protein linked to increased severity of symptoms in Familial Mediterranean Fever (FMF). We consider that inflammation due to MEFV variants would increase eye inflammation and damage aqueous humor regulation. The present study is the first analysis investigating a MEFV (E148Q) variant as a marker protecting from glaucoma.

Methods: In this prospective clinical analyze, we performed detailed gene sequencing focusing on 22 specific regions of the pyrin (MEFV) gene. The study involved two distinct groups: individuals diagnosed with glaucoma (n = 200) and control subjects without glaucoma (n = 100). Both groups were carefully selected to exclude individuals with symptoms or a previous diagnosis of Familial Mediterranean Fever (FMF). The diagnosis of glaucoma for each participant was rigorously established through comprehensive direct ophthalmic examinations.

Results: A significant odds ratio for protection against glaucoma was found in carriers of the subclinical E148Q allele (OR:2.22; 95%CI: 1.098-4.485). No significant differences were found for other variants. One mutant E148Q-allele could decrease the probability of glaucoma development by approximately 68,9%. We observed no differences in the genotype frequency between glaucoma and healthy for the other MEFV gene variants.

Conclusion: The pyrin variant of the MEFV gene resulting in a subclinical phenotype appears to reduce the incidence of glaucoma, and heterozygous pyrin (MEFV) E148Q allele carriers confer protection against glaucoma. It is important to consider the limitations arising from the relatively small number of studies conducted on this topic.