TGFBI gene mutation in a Chinese pedigree with Reis-Bücklers corneal dystrophy.

PURPOSE: To characterize the molecular defects in the TGFBI gene in a Chinese family with Reis-Bücklers corneal dystrophy (RBCD), and to study the relationship between the gene mutations and the clinical manifestations.

METHODS

Four generations of this family with RBCD were enrolled in the study. In addition to ophthalmic and histopathological examinations, polymerase chain reaction (PCR) amplification and analysis of nucleotide sequencing of exons 4, 12, 14 of TGFBI were performed.

RESULTS

The clinical manifestations of the disease were characterized by geographic opacities in the subepithelial layers and anterior stroma of the cornea. Confocal microscopy images of the cornea showed focal hyper-reflective materials deposited in the subepithelium and anterior stroma. It was confirmed by histopathology that Bowman's membrane was mainly replaced by extracellular fibril material, which extended downwards into the superficial corneal stroma. Molecular genetic analysis revealed a single heterozygous G>T change at nucleotide 124 in exon 4 of TGFBI in all members (22) of the pedigree affected with RBCD, but not in the unaffected members.

CONCLUSIONS

A p.Arg124Leu mutation of the TGFBI gene was detected in this Chinese pedigree with Reis-Bücklers corneal dystrophy. The phenotype of Reis-Bücklers corneal dystrophy in this family belongs to the geographic type. The molecular genetic studies combined with histopathology may be useful for the accurate diagnosis of this type of corneal dystrophy.