Abstract
Abstract: :
Purpose: BIGH3 gene has been identified as a candidate gene for corneal dystrophies that mapped to chromosome 5q31. Each form of the 5q31-linked autosomal dominant corneal dystrophies has been associated with a different mutation. Current molecular biologic knowledge of corneal dystrophies suggests the existence of a phenotype-genotype correlation. Our aim was to identify the underlying mutations and polymorphisms in our British families and sporadic patients with Reis Bückler's (RBCD), Granular (GCD), Lattice type I (LCDI), and Avellino corneal dystrophy (ACD). Methods: 36 patients, 10 sporadic subjects and 26 patients who are members of families were included in the study. 10 ml venous blood samples were taken, DNA was extracted and the BIGH3 gene was amplified by the polymerase chain reaction (PCR). The amplified products were analysed by direct sequencing and restriction digest analyses. Results: Four different missense mutations has been detected in the coding region of BIGH3 gene, R124C for LCDI, R124H for ACD, R555Q for RBCD, and R555W for GCD which were similar to those reported previously in patients from other ethnic origins. Also, we identified seven nucleotide substitutions that did not change the amino acid sequence of the encoded protein. Four of these were novel. Conclusions: In our patients of British origin, each phenotype of the corneal dystrophies studied has been linked to a particular point mutation of the BIGH3 gene.
Keywords: cornea: clinical science • genetics • degenerations/dystrophies