Mutation spectrum of the LRP5, NDP, and TSPAN12 genes in Chinese patients with familial exudative vitreoretinopathy

Abstract

PURPOSE. LRP5, NDP, and TSPAN12 are known to be associated with familial exudative vitreoretinopathy (FEVR). In this study, a comprehensive mutation screening for the three genes was performed in patients with a clinical diagnosis of FEVR in Han Chinese. METHODS. Genomic DNA and clinical data were collected from 100 probands and their family members. Sanger sequencing was performed to screen for LRP5, NDP, and TSPAN12 mutations and phenotype-genotype correlation was analyzed. RESULTS. There were 23 causative mutations identified in 23 unrelated probands (10/23 in LRP5, 8/23 in TSPAN12, and 5/23 in NDP). Apart from NDP mutations, only two LRP5 mutations inherited in an autosomal recessive manner. Among the 23 causative mutations, 13 were novel variants (4/10 in LRP5, 6/8 in TSPAN12, and 3/5 in NDP). According to the modified classification system, statistical significance was observed in the distribution of mutated genes (P = 0.049). None of the causative mutations was found in group I FEVR. Probands with LRP5 or NDP mutations were mainly categorized into group III and IV, TSPAN12 mutations were mainly observed in probands with group IV and V FEVR. CONCLUSIONS. The detection rate for mutations in the three known genes was 23%. Mutations in LRP5 and TSPAN12 were more frequent, accounting for 10% and 8%, respectively. The NDP mutations were only identified in 6% in this cohort. There were 13 novel variants found, which provided a deeper understanding of this disease. Potential phenotype-genotype correlation was observed in the modified system. TSPAN12 mutations might lead to the most severe phenotype.