Whole-Exome Sequencing Analysis Identified Novel Mutations in the TSPAN12 Gene in Chinese Families with Familial Exudative Vitreoretinopathy

Background: Familial exudative vitreoretinopathy (FEVR, OMIM 133780), characterized by incomplete retinal vascular development and pathological neovascularization, is a severe inherited retinal disorder. Mutations in 10 genes have been reported to be associated with FEVR, but this still leaves similar to 50% of FEVR cases to be genetically explained. Purpose: The purpose of this study was to identify novel FEVR-causing mutations and explore the causative mutations in Chinese FEVR families. Methods: Whole-exome sequencing was performed to analyze the genomic DNA of the probands from 121 Chinese FEVR families. Sanger sequencing was carried out to verify all identified mutations. Luciferase assays were used to test the activity of a mutant protein in the Norrin-beta-catenin signaling pathway. Results: Four novel heterozygous TSPAN12 (Tetraspanin 12) mutations, including two single-base substitution mutations and two small-deletion mutations, were identified in these FEVR families: c.1A>G (p.0), c.614G>A (p.G205D), c.695delT (p.V232Gfs*7), and c.833_842del (p.L278Qfs*25). Conclusion: This study revealed the causative mutations in four Chinese FEVR families and identified four novel FEVR-causing mutations, thus expanding the mutation spectrum of FEVR in the Chinese population.