A novel beaded filament structural protein 1 (BFSP1) gene mutation associated with autosomal dominant congenital cataract in a Chinese family

PURPOSE To identify the disease-causing mutation in a five-generation Chinese family affected with bilateral congenital nuclear cataract. METHODS Linkage analysis was performed for the known candidate genes and whole-exome sequencing was used in two affected family members to screen for potential genetic mutations; Sanger sequencing was used to verify the mutations throughout family. RESULTS A novel beaded filament structural protein 1 (BFSP1) gene missense mutation was identified. Direct sequencing revealed a heterozygous G>A transversion at c.1042 of the coding sequence in exon 7 of BFSP1 (c.1042G>A) in all affected members, which resulted in the substitution of a wild-type aspartate to an asparagine (D348N). This mutation was neither seen in unaffected family members nor in 200 unrelated people as controls. CONCLUSIONS A novel mutation (c.1042G>A) at exon 7 of BFSP1, which creates a substitution of an aspartate to an asparagine (p.D348N) was identified to be associated with autosomal dominant congenital cataract in a Chinese family. This is the first report of autosomal dominant congenital cataract being associated with a mutation in BFSP1, highlighting the important role of BFSP1 for physiological lens function and optical properties.