Distribution of Gene Mutations in Chinese Sporadic Congenital Cataracts. Homo sapiens

The purpose of this study was to investigate the genetic effects underlying non-hereditary sporadic congenital cataracts (SCC). We collected DNA samples from 74 SCC patients and 20 traumatic cataract (TC) patients in the matched age group as normal controls and performed genomic sequencing of 61 lens-related genes by target region capture and next generation sequencing. By filtering against common variants in public database or were associated with TC cases, we identified 94 SCC-specific variants in 46 genes from 49 patients. Among the mutated genes, GALK1 had the highest mutation frequency with mutations detected 10 times in 7 patients; followed by FBN1 and ADAMTSL4, the mutation of which were detected 6 times in 6 patients. We observed that 6 out of 7 patients with GALK1 mutations had the phenotype of posterior polar cataract while the mutations of other tested genes did not show significant preference to a specific subtype of cataract morphology. From this study, we confirmed the clinical and genetic heterogeneity of congenital cataracts and conclude that genetic mutations could be important contributing factors to SCC. This is the first study to report broad spectrum genotyping on SCC subjects.