New mutation p.Glu48Gly in the GJA8 gene in a compound heterozygous state in a patient with sporadic congenital zonular cataract

Abstract

Significant clinical and genetic heterogeneity of hereditary cataracts significantly complicates their early DNA diagnosis and determines the relevance of studying the epidemiology of the disease, population features of the spectrum and frequencies of mutations in responsible genes, clinical and genetic correlations. Mutations in the connexin 50 (GJA8) gene are common causes of hereditary, mainly autosomal dominant, congenital cataracts. In a patient with congenital bilateral zonular cataract in the GJA8 gene two nucleotide substitutions were identified in the compound heterozygous state - the previously undescribed missense variant C.143A>G (p.Glu48Gly) and the known nucleotide variant C.741T>G (p.Ile24Met). Based on clinical genealogical and molecular genetic analysis, the sporadic nature of the disease in the family was established. The newly identified variant of p.Glu48Gly is presumably a pathogenic mutation showing a recessive character.