Novel mutations of RPGRIP1 gene in a family with Leber congenital amaurosis

Abstract

Objective To identify the pathogenic gene mutations in a family with Leber congenital amaurosis (LCA). Methods In October 2018, 1 patient and 3 normal family members from a LCA family was enrolled in this retrospective study. Detailed medical history of proband was obtained and fixation test, cycloplegic refraction, slit-lamp, fundus color photography and full-field ERG were performed. And other family members underwent BCVA, refraction slit-lamp, fundus biomicroscopy with the slit lamp, fundus color photography and full-field ERG. The family was investigated with a specific hereditary eye disease enrichment panel which contained 441 known pathogenic genes and based on targeted exome capture technology first to indentify the potential pathogenic genes and mutations. Then the potential pathogenic mutations were conformed by Sanger sequencing. Finally, the results were analyzed via bioinformatics analysis. Results The proband showed no trace object from childhood, but had obvious photophobia and nystagmus. No positive changes were found in the anterior segment, vitreous and retina in both eyes. Both cone and rod system function decreased significantly in full-field ERG in both eyes. Gene tests showed the proband carried both RPGRIP1 c.1635dupA and c.3565C> T, which composited a heterozygous mutation. Bioinformatics analysis showed RPGRIP1 c.1635dupA was a pathogenic mutation, and RPGRIP1 c.3565C> T which was a novel potential pathogenic mutation in LCA. Conclusion The compound heterozygous mutation, c.1635dupA and c.3565C> T in RPGRIP1 may be responsible for the pathogenesis in this Chinese Han LCA pedigree. Key words: Leber congenital amaurosis/etiology; Genes; Mutation; RPGRIP1 gene