Novel Mutations Identified in the Chinese Han Population with Keratoconus by Next-Generation Sequencing.

ABSTRACT

AIM: To identify novel mutations in keratoconus (KC) susceptibility genes in the Chinese Han population. METHODS: A total of fifty-two patients with primary KC were recruited. Blood samples were collected, and genomic DNA was isolated from peripheral blood leukocytes. The entire coding region, intron-exon junctions, and promoter regions of sixteen known KC susceptibility genes were screened with next-generation sequencing technology. All identified variants were further confirmed using the Sanger sequencing technology. The Sorting Intolerant from Tolerant (SIFT), MutationTaster, and PolyPhen 2 programs were used to predict the effect of amino acid substitution on protein. RESULTS: After removing twelve known SNPs (single nucleotide polymorphisms) and three variants predicted to be harmless, nine novel mutations were identified in eight of the fifty-two patients, including c.455C > Tp.P152L in FNDC3B; c.3636_3637delp.R1212fs in COL4A4; c.5015G > Tp.R1672L, c.3798dupAp.P1267fs, and c.28G > Ap.A10T in MPDZ; c.1940C > Tp.P647L in DOCK9; c.127_128insGGCp.Q43delinsRQ in POLG; c.3019G > Ap.V1007I in IPO5; and c.624 + 7- > A in TGFBI. All nine mutations in the patients with KC were heterozygote. CONCLUSION: This study enlarged the gene profile of KC and should be further confirmed by well-powered, genome-wide association studies (GWAS) of Han Chinese patients.