Genetic analysis by whole exome sequencing (WES) in a patient with retinal disorder: A Case Study

Objective: Retinal hemangioblastoma is part of the symptoms of von Hippel-Lindau (VHL) syndrome, which occurs due to mutations in the VHL gene located on chromosome 3. This gene encodes a protein that plays important roles such as regulating the expression of oxygen-related genes, cilia formation, extracellular matrix formation, etc. Mutations in this gene cause hemangioblastomas of the retina, brain, and spinal cord, as well as a wide range of symptoms such as kidney and pancreatic cysts, etc.Materials and Methods: This is a laboratory and experimental study in which a female patient suddenly developed blindness in her right eye at the age of 23. After ophthalmological examinations by specialists, blood was taken from the patient to find the main cause of the disease and genetic study, and DNA extraction was performed using the saturated salt method. Then, whole exome sequencing (WES) was performed, and finally, to confirm the candidate mutation and the results of WES, Sanger sequencing was performed.Results: Based on the findings of this study, a mutation occurred in chromosome number 3 and at position Chr3-10191469 A G:NM_000551:exon3: c.464-2A>G of the VHL gene, in which a nucleotide with a guanine base was replaced by an adenine nucleotide. This mutation is pathogenic and its inheritance is autosomal dominant, and the patient's genotype for this gene was heterozygous, which was directly related to his phenotype and led to the development of von Hippel-Lindau syndrome and impaired retinal function in his right eye.