A Gene Scan Study of RPE65 in Chinese Patients with Leber Congenital Amaurosis

Background: Leber congenital amaurosis (LCA) is a visual disease which is caused by RPE65 mutations and results in retinal degeneration and severe vision loss in early infancy. According to previous researches, mutations of the RPE65 gene account for 16% of all cases of LCA. This study aimed to identify RPE65 gene mutations in Chinese patients with LCA. Methods: We recruited 52 sporadic patients from Peking University Third Hospital in 2016 and applied Sanger sequencing to identify variants among exons responsible for the disease. The genomic DNAs from blood leukocytes of these patients were isolated, and the entire coding region of the RPE65 gene was amplified by polymerase chain reaction. We then determined the sequence of RPE65 using ABI 3100 Genetic Analyzer. Results: Our study identified that only 1 out of the 52 patients with LCA carried the previously unreported homozygosis missense mutation c1174A>C (T392P) of the RPE65 gene. However, the mutation was associated with the disease phenotype and not detected in 100 normal controls. Conclusions: Though we identified a novel missense mutation in the RPE65 gene that causes LCA, our result indicates that RPE65 mutations may not play a major role in the LCA patients in China since only 1 out of the 52 patients carried mutation in the RPE65 gene.