Revealing Molecular Diagnosis With Whole Exome Sequencing in Patients With Inherited Retinal Disorders

Abstract

Inherited retinal diseases (IRDs) constitute a heterogeneous group of clinically and genetically diverse conditions, standing as a primary cause of visual impairment among individuals aged 15-45, with an estimated incidence of 1:2000. Our study aimed to comprehensively evaluate the genetic variants underlying IRDs in the Turkish population. This study included 50 unrelated Turkish IRD patients and their families. Genomic DNA was extracted from each participant, and candidate variants were identified via next-generation sequencing to determine their pathogenicity. We detected variants in 58% of the patients, of which six novel variants were identified. Among these, 16 cases exhibited variants associated with retinitis pigmentosa and Stargardt disease, while 13 presented variants linked to other retinal diseases. The spectrum of identified variants included 21 homozygous cases and five compound heterozygous variants, both indicative of autosomal recessive inheritance. Three cases revealed heterozygous variants suggestive of autosomal dominant inheritance, and two cases featured hemizygous variants suggestive of X-linked inheritance. Importantly, no matches with copy number variants were detected in our analysis. This study comprehensively portrays clinical and genetic profiles within the Turkish population affected by IRDs. Identifying novel variants and delineating inheritance patterns contribute to a deeper understanding of the genetic diagnosis of IRDs, paving the way for more precise diagnostic and therapeutic interventions.