Next generation sequencing-based molecular diagnosis in familial congenital cataract expands the mutational spectrum in known congenital cataract genes

Congenital cataract (CC) is a significant cause of childhood blindness worldwide. CC is a genetically heterogeneous disease because mutations in over 40 genes have been demonstrated to cause the disorder and up to 40% of cases arise from single-gene mutations. Hence, next generation sequencing (NGS) of deoxyribonucleic acid is a suitable approach for CC molecular diagnosis. In this study, we used commercially available inherited disease NGS panels including 50 CC genes for the genetic diagnosis of 11 probands with hereditary CC. Causal variants were recognized in six families. A novel CRYGC variant, p.(Phe6Ser), was identified in two apparently unrelated families. Two additional novel variants in the crystallin genes CRYBB2 (p.[Gly149Asp]) and CRYGA (p.[Arg48Cys]) were also identified. One family carried the novel p.[Gly8_Leu11del] variant in GJA8, while another family exhibited the previously reported c.2826-9G>A pathogenic change in EPHA2. Our results illustrate the utility of NGS for diagnosing CC in our population, and our results contribute to expand the mutational spectrum with four novel pathogenic variants in known CC genes.