A novel H572R mutation in the transforming growth factor-β-induced gene in a Thai family with lattice corneal dystrophy type I

Abstract

Purpose: To describe a large Thai family with lattice corneal dystrophy (LCD) type I and to determine whether this LCD is associated with mutations within the transforming growth factor-β-induced (TGFBI) gene. Methods: A six-generation family with LCD type I was identified and diagnosed on the basis of clinical and/or histopathologic evaluation. Visual acuity testing and slit-lamp biomicroscopic evaluation were carried out and corneal photography was documented. All 17 exons and flanking intron sequences of the TGFBI gene were sequenced. Results: Thirty-three participants demonstrated LCD in both eyes, most of which was symmetrical. Age at onset of decreased vision was the mid- to late twenties. Visual acuity varied from 6/6 to no light perception. Two patients, 74 and 42 years of age, demonstrated a thick yellowish plaque covering the corneal surfaces. DNA sequencing revealed a heterozygous mutation in exon 13 (A1762G), changing histidine to arginine at codon 572 (H572R). Ten of 42 clinically unaffected family members, all under 25 years of age, exhibited the same mutation. Conclusions: This is the first report of a molecular analysis of LCD type I in Thai patients. The novel mutation identified is associated with distinct phenotypes and later onset of the disease compared with the more common R124C mutation. © Japanese Ophthalmological Society 2006.