R124C and R555W TGFBI mutations in Spanish families with autosomal-dominant corneal dystrophies.

PURPOSE

Mutations in the transforming growth factor beta I (TGFBI) gene cause several types of autosomal-dominant corneal dystrophies. We investigated the role of this gene in two Spanish families affected by lattice type I or granular type I corneal dystrophies.

METHODS

We recruited 13 subjects from two unrelated families diagnosed with autosomal dominant lattice type I or granular type I corneal dystrophies. Corneal phenotypes were assessed by slit lamp examination. Genomic DNA was obtained from blood samples, and exons 4, 11, 12, and 14, which contained mutation hot spots of the TGFBI gene, were screened for mutations by PCR DNA sequencing.

RESULTS

We identified two TGFBI mutations: R124C (exon 4), which segregated with lattice type I corneal dystrophy, and R555W (exon 12), which segregated granular type I corneal dystrophy. Two single-nucleotide polymorphisms were also found, of which H428H was novel and F540F was previously reported.

CONCLUSIONS

This is the first report of mutations in the TGFBI gene in Spanish families affected by corneal dystrophy. R124C and R555W TGFBI mutations cause lattice and granular type I corneal dystrophies in the studied families. Our results indicate that the genetic defects underlying corneal dystrophies in Spanish patients are similar to those found in other populations.