A Novel Mutation in the FYCO1 Gene Causing Congenital Cataract: Case Study of a Chinese Family

Abstract

Congenital cataract is the most important global cause of visual impairment in children. Autosomal dominant and autosomal recessive inheritance account for the majority of the hereditary nonsyndromic congenital cataract. The function of FYCO1 gene is to guide the transport of the microtubule-directed vesicles. Mutations in the FYCO1 gene may cause cataracts. We reported a novel nonsense mutation in FYCO1 ( $\text{c}.1411\text{C}>\text{T}$ , P. R471 $\ast$ ), which could cause nonsyndrome autosomal recessive congenital cataract. We underwent an ophthalmology examination of all participants and collected blood samples from all participants and extracted genomic DNAs. By whole exome sequencing, we found that this family carried an unreported mutation in the FYCO1 gene: $\text{c}.1411\text{C}>\text{T}$ , P. R471 $\ast$ . Sanger sequencing was performed to verify the mutation. We used ITASSER and PYMOL to predict and compare the structure and function of the mutated proteins. Using SIFT software and referring to the relevant guidelines of ACMG, the mutation was determined to be pathogenic. The models suggested that the nonsense mutation p.R471 $\ast$ resulted in a profound disruption of the FYCO1 protein structure. This report expands the locus information of the FYCO1 mutations.