THE CLASSIC FORM OF GRANULAR CORNEAL-DYSTROPHY ASSOCIATED WITH R555W MUTATION IN THE BIGH3 GENE IS RARE IN JAPANESE PATIENTS

PURPOSE: To identify the BIGH3 gene mutation in 10 unrelated Japanese individuals with granular corneal dystrophy. METHODS: Genomic DNA was obtained from each patient's leukocytes. Exons 4 and 12 of the BIGH3 g ene were amplified by polymerase chain reaction and were directly sequ enced. RESULTS: Nine of these patients were found to have the R124H mu tation, whereas only one had the R555W mutation. Slit-lamp examination showed that the granular corneal dystrophy associated with each mutat ion is different, CONCLUSIONS: These results, together with our previo us findings, show that the classic form of granular corneal dystrophy associated with the R555W mutation is rare in Japanese patients, where as granular corneal dystrophy accompanied by amyloid deposits and asso ciated with the R124H mutation, Avellino corneal dystrophy, is more co mmon. Direct examination may be insufficient in the proper diagnosis o f corneal dystrophy, and BIGH3 mutation analysis may be required. (C) 1998 by Elsevier Science Inc. All rights reserved.