Association of autosomal dominantly inherited corneal dystrophies with BIGH3 gene mutations in Japan.

PURPOSE: To evaluate the incidence of BIGH3 gene mutations in 164 unrelated Japanese patients with corneal stromal dystrophies with an autosomal dominant trait.

METHODS: Data were collected at two major institutions in the eastern and western parts of Japan, where molecular genetic analysis was performed for diagnostic purpose.

RESULTS: The incidence of mutations was ranked as follows: 118 patients (72%), the R124H mutation associated with Avellino corneal dystrophy; 23 patients (14%), the R124C mutation associated with lattice corneal dystrophy type 1; and 10 patients (6%), the P501T mutation associated with lattice corneal dystrophy type 3A.

CONCLUSION: Avellino corneal dystrophy associated with the R124H mutation is the most common form of corneal stromal dystrophy in Japan. This dystrophy, which is diagnosed histopathologically, has also been called granular corneal dystrophy in Japan. The classification of these diseases according to genetic pathogenesis may be more appropriate than is the use of clinical or histological findings.