Clinical and Genetic Characteristics Analysis of Korean Patients with Stargardt Disease Using Targeted Exome Sequencing

Abstract

Purpose: To investigate genetic mutations in Korean patients with Stargardt disease (STGD) using exome sequencing, and to analyze the correlations between genetic mutations and clinical phenotypes. Methods: Peripheral venous blood was obtained from 24 clinically diagnosed Korean STGD patients, followed by extraction of genomic DNAs. Using exome sequencing we investigated gene mutations for the adenosine triphosphate-binding cassette, subfamily A, member 4 (ABCA4) elongation of very-long-chain fatty acids 4 (ELOVL4), and prominin 1 (PROM1), and confirmed gene mutations by the direct sequencing of polymerase chain reaction products. Results: ABCA4 mutations were confirmed in 17 of 24 patients, and 12 novel mutations were identified. ELOVL4 and PROM1 gene mutations were not identified in this study. We also identified 16 previously reported mutations related to STGD1. In patients whose disease symptoms occurred before 20 years of age, visual acuity was poorer and atrophic flecks were more frequently found. In addition, more ABCA4 mutations were found in patients who had choroidal silence or atrophic flecks. Conclusions: Novel ABCA4 gene mutations were found in Korean patients with STGD1. This study will facilitate better understanding of the relationships between ABCA4 gene mutations and clinical symptoms in Korean patients.