Discovery of New Mutation Sites of KIF21A Gene in Chinese Patients with Congenital Fibrosis of the Extraocular Muscles

Abstract

Background Congenital fibrosis of the extraocular muscles (CFEOM) is a rare hereditary nonprogressive disorder characterized by bilateral ptosis, which shows severely limited ocular motility. We reported a new mutation site of KIF21A gene in a Chinese family with congenital fibrosis of the extraocular muscles type 1 (CFEOM1).Methods A retrospective study of case series was conducted in this study. Standard ocular examinations were performed on 10 family members in a CFEOM1 family. Next-generation sequencing (NGS) was performed to sequence 828 genes related to oculopathy. The splice sites of the KIF21A gene were analyzed to detect the existence of mutations.Results The five patients with CFEOM1 were found in the family members of a Chinese family on three generations. A new KIF21A pathogenic SNP mutation site KIF21A-ex20 c.2821C > T (p.Arg941Trp) was identified by comparing with human genome reference genes and Sanger sequencing. .Conclusions A new KIF21A pathogenic SNP mutation site KIF21A-ex20 c.2821C > T (p.Arg941Trp) could possibly be a major disease‑causing gene for the Chinese family with CFEOM1.