Highly efficient capture approach for the identification of diverse inherited retinal disorders.

Our study presents a 319-gene panel targeting inherited retinal dystrophy (IRD) genes. Through a multi-center retrospective cohort study, we validated the assay's effectiveness and clinical utility and characterized the mutation spectrum of Taiwanese IRD patients. Between January 2018 and May 2022, 493 patients in 425 unrelated families, all initially suspected of having IRD without prior genetic diagnoses, underwent detailed ophthalmic and physical examinations (with extra-ocular features recorded) and genetic testing with our customized panel. Disease-causing variants were identified by segregation analysis and clinical interpretation, with validation via Sanger sequencing. We achieved a read depth of >200× for 94.2% of the targeted 1.2 Mb region. 68.5% (291/425) of the probands received molecular diagnoses, with 53.9% (229/425) resolved cases. Retinitis pigmentosa (RP) is the most prevalent initial clinical impression (64.2%), and 90.8% of the cohort have the five most prevalent phenotypes (RP, cone-rod syndrome, Usher's syndrome, Leber's congenital amaurosis, Bietti crystalline dystrophy). The most commonly mutated genes of probands that received molecular diagnosis are USH2A (13.7% of the cohort), EYS (11.3%), CYP4V2 (4.8%), ABCA4 (4.5%), RPGR (3.4%), and RP1 (3.1%), collectively accounted for 40.8% of diagnoses. We identify 87 unique unreported variants previously not associated with IRD and refine clinical diagnoses for 21 patients (7.22% of positive cases). We developed a customized gene panel and tested it on the largest Taiwanese cohort, showing that it provides excellent coverage for diverse IRD phenotypes.

Mutation spectrum and genotype-phenotype correlation of inherited retinal dystrophy in Taiwan.

BACKGROUND: Inherited retinal dystrophy (IRD) is a group of irreversible retinal degenerative disorders with significant genotypic and phenotypic heterogeneity, which cause difficulty in making a precise clinical diagnosis. Furthermore, the mutation spectrum of IRD in Taiwan remains unknown. Therefore, our study focused on investigating the spectrum of mutations among Taiwanese families with IRD using targeted exome sequencing (TES) technology. METHODS: We recruited a total of 60 unrelated Taiwanese families with IRD; most of them were retinitis pigmentosa. We employed TES to investigate 284 candidate genes. Bioinformatics analysis, Sanger sequencing-based co-segregation testing, and computational assessment were performed to validate each mutation and its pathogenicity. The genotype-phenotype correlation was analysed in all patients with mutations defined in the guidelines provided by the American College of Medical Genetics. RESULTS: We successfully identified genetic causes in 32 families (detection rate of 53.3%). Among them, 16 had a sporadic inheritance (16/36, 44.4%); eight had an autosomal recessive inheritance (8/14, 57.1%); four had an autosomal dominant inheritance (4/5, 80%); four had an X-linked inheritance (4/5, 80%). Among 38 pathological mutations in 19 known genes, 20 mutations are reported here for the first time. Novel mutation spectrum and genotype-phenotype correlations were revealed as well. CONCLUSION: Here we achieved a detection rate of 53.3% and elucidated the mutation spectrum in Taiwanese families with IRD for the first time. The results indicated that CYP4V2 and USH2A might be the most common pathogenic genes in IRD patients in Taiwan.

Genotype-Phenotype Association Study Reveals CFI-Rs13104777 to be a Protective Genetic Marker Against Acute Anterior Uveitis.

PURPOSE: To investigate the roles of CFI, genotype-phenotype associations were identified in AAU. METHODS: A case-control study was conducted in a total of 575 subjects consisting of 279 AAU patients and 296 healthy controls. Genotypic analyses were performed using Sequenom MassARRAY technology. Analyses were stratified to a series of clinical ophthalmic confounding factors. RESULTS: A lower frequency of the CFI-rs13104777 C allele was found in the AAU cohort compared with the controls, and, thus, was significantly associated with AAU pathogenesis (p = 0.041, OR = 0.712, 95% CI: 0.513-0.987). Stratified analysis also demonstrated the associations may differ depending on the HLA-B27 status and laterality status. CONCLUSIONS: This study has revealed a significant genetic role for CFI-rs13104777 in AAU. This influence may be dependent on human leukocyte antigen (HLA)-B27 and disease laterality. Overall, the results provide evidence for a pathogenic role for CFI in AAU and expand our knowledge on the genetic basis of AAU.

Investigation of the association between interleukin-1beta polymorphism and normal tension glaucoma.

PURPOSE: In normal tension glaucoma (NTG), factors other than elevated intraocular pressure are likely to have a role in the pathogenesis of optic neuropathy. The potential similarities in cellular apoptosis leading to neurodegeneration between Alzheimer's disease and NTG were shown in recent studies. The interleukin-1beta (IL-1beta; -511) and IL-1beta (+3953) polymorphisms were found to increase risk with Alzheimer's disease. The purpose of this study was to test the hypothesis that the IL-1beta polymorphism is associated with NTG in the Chinese population. METHODS: This is a cohort study in a Chinese population that involved 231 people with NTG and 245 healthy controls. Genomic DNA was amplified by a polymerase chain reaction, followed by the enzymatic restriction fragment length polymorphism technique. Patients and controls were genotyped for the C/T polymorphism at position -511 and +3953 of the IL-1beta gene. Genotypes for NTG and control groups were compared for statistically significant differences. RESULTS: There was no significant difference in genotype frequency or allele frequency distribution of the IL-1beta gene polymorphisms (position -511 and +3953) between NTG patients and the control group (p >0.3). CONCLUSIONS: Our study showed no evidence for an association between the IL-1beta (-511) and IL-1beta (+3953) polymorphisms and NTG. The IL-1beta gene polymorphisms (position -511 and +3953) may not play a key role in NTG pathogenesis in Chinese population.

Normal tension glaucoma is not associated with the interleukin -1alpha (-889) genetic polymorphism.

BACKGROUND: Factors other than intraocular pressure are likely to play a role in the pathogenesis of glaucomatous optic neuropathy, particularly in individuals with normal tension glaucoma (NTG). Recent laboratory evidence has shown that there are potential similarities between Alzheimer disease and NTG in cellular apoptosis leading to neurodegeneration. IL-1alpha (-889) T allele polymorphism has been found to increase the risk of developing Alzheimer disease. The aim of this study was to test in a Chinese cohort the hypothesis that IL-1alpha (-889) polymorphism is associated with NTG. METHODS: One hundred sixty-two unrelated patients with NTG were recruited and compared with 167 controls in a Chinese population. Genomic DNA was amplified by polymerase chain reaction, followed by enzymatic restriction fragment length polymorphism technique. Patients and controls were genotyped for the C/T polymorphism at position -889 of the IL-1alpha gene promoter region. RESULTS: There was no significant difference in the frequency of IL-1alpha (-889) alleles or genotypes in the NTG population compared with that in the control group. CONCLUSIONS: We conclude that C/T polymorphism at position -889 of the IL-1alpha gene promoter region does not increase the risk of developing NTG. However, further studies on NTG are necessary to investigate the genetic basis and factors involved in the development of the neurodegenerative process.

Polymorphism in the IL-1alpha (-889) locus associated with elevated risk of primary open angle glaucoma.

PURPOSE: Recent laboratory evidence indicates that the inflammatory cytokine, interleukin-1 (IL-1), has either protective or adverse effects on primary open angle glaucoma (POAG). Inheritance of the IL-1alpha (-889) polymorphism (the T allele), previously shown to increase IL-1 production, has been associated with an elevated risk of Alzheimer's disease. The neuronal injuries associated with Alzheimer's disease have a number of similarities with the optic nerve changes often seen with POAG. In this report we have explored the possible association between the IL-1alpha (-889) polymorphism and the development of POAG. METHODS: Chinese patients with POAG (156) were recruited and compared with 167 healthy chinese controls. Genomic DNA was amplified by polymerase chain reaction, followed by enzymatic restriction fragment length polymorphism technique (PCR-RFLP). Patients and controls were genotyped for the C/T polymorphism at position -889 of the IL-1alpha gene promoter region. RESULTS: The frequency of the IL-1alpha (-889) T allele (21% versus 13%, respectively; p=0.007) and the carriers of the IL-1alpha (-889) T allele (37% versus 25%; p=0.019, OR 1.76, 95%CI 1.1-2.83) were greater in POAG patients compared with controls. There is a higher risk of POAG associated with homozygosity for the IL-1alpha (-889) T allele (TT genotype) compared with the control population (CC genotype; 5% versus 1%, respectively, p=0.04; OR 5.1, 95% CI 1.19-21.66). CONCLUSIONS: The IL-1alpha (-889) T allele polymorphism, previously shown to increase IL-1 gene expression, may be a risk factor in the development of POAG.