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

Abstract

To characterize the betaig-h3 gene defect in a French family affected with lattice corneal dystrophy type IIIA (LCDIIIA). Histologic examination was performed from corneal buttons of two patients. Genomic DNA was extracted from leukocytes, and exons of the betaig-h3 gene were amplified by polymerase chain reaction to be directly sequenced. 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. In contrast to Japanese patients, these French patients affected with LCDIIIA carry a distinct mutation of the betaig-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.