A new mutation (A546T) of the βig-h3 gene responsible for a French lattice corneal dystrophy type IIIA

Abstract

PURPOSE: To characterize the βig-h3 gene defect in a French family affected with lattice corneal dystrophy type IIIA (LCDIIIA).

METHODS: Histologic examination was performed from corneal buttons of two patients. Genomic DNA was extracted from leukocytes, and exons of the βig-h3 gene were amplified by polymerase chain reaction to be directly sequenced.

RESULTS: Numerous deposits were evident in the stroma and beneath the Bowman membrane, which had all the features of amyloid deposits. Analysis of exon 12 revealed a heterozygous G to A transition on codon 546.

CONCLUSION: In contrast to Japanese patients, these French patients affected with LCDIIIA carry a distinct mutation of the βig-h3 gene (A546T instead of P501T). Therefore, it is unclear whether different mutations could result in the same dystrophy or whether we are dealing with clinical heterogeneity of LCDIIIA.