Objective: To study whether Chinese patients with various corneal dystrophy carry mutations in BIGH3 gene.
Methods: Genomic DNA was extracted from Chinese patients with Avellino corneal dystrophy (ACD, 10 cases), Reis-Bücklers corneal dystrophy (CDRB, 2 cases), granular corneal dystrophy (GCD, 3 cases) and 5 control subjects. The exons 4 and 12 of BIGH3 gene were amplified by PCR and the product was sequenced directly.
Results: All 15 patients carried mutations in BIGH3 gene, R124H in 10 cases with ACD, R124L in 2 cases with CDRB and R555W in 3 cases with GCD.
Conclusions: Corneal lesions in all 15 Chinese patients clinically diagnosed with corneal dystrophies are caused by mutations in BIGH3 gene. Dose-effect analysis shows that corneal lesions are more severe in homozygous patients than those in heterozygous cases and that clinical manifestation of patients with R124L mutation is more severe than that of patients with R124H mutation.