Q118X mutation of M1S1 gene caused gelatinous drop-like corneal dystrophy:The P501T of BIGH3 gene found in a family with gelatinous drop-like corneal dystrophy

PURPOSE: To analyze BIGH3 and M1S1 genes in two Japanese brothers with gela tinous drop like corneal dystrophy and five unaffected family members. METHODS: DNA was extracted, and each part of the two genes was amplified an d directly sequenced. RESULTS: On the BIGH3 gene, a heterozygous P501T mutation was found in the elder brother and three unaffected family members. On the M1S1 gene, both b rothers with gelatinous drop-like corneal dystrophy showed a homozygous Q11 8X mutation, whereas all unaffected members were heterozygous. CONCLUSIONS: The Q118X mutation of M1S1 gene caused gelatinous drop-like co rneal dystrophy, Although the P501T of the BIGH3 gene found in this pedigre e was precisely the one reported for lattice corneal dystrophy IIIA, no cli nical feature was shown, even in the 85-year-old father. This fact shows th at the P501T mutation for LCDIIIA has low penetrance. (C) 2000 by Elsevier Science Inc. All rights reserved.