[A research on TGFBI gene mutations in Chinese families with corneal dystrophies].

OBJECTIVE: To identify what kind of TGFBI gene mutation happening to Chinese patients with corneal dystrophies. METHODS: Three Chinese families with stromal corneal dystrophies and one Chinese family with Thiel-Behnke corneal dystrophies were studied, of whom three were Han race and another was Mongolia race in China. All members of families were examined clinically and their genomic DNAs were extracted from blood leukocytes. Thirteen exons in TGFBI gene were amplified by polymerase chain reaction (PCR) and directly sequenced for molecular analysis. RESULTS: Mutations in TGFBI gene were detected from all the patients with corneal dystrophy, but not found in normal subjects of families. The mutation R555W was found and identified from the family with granular corneal dystrophy; R555Q from the family with Thiel-Behnke corneal dystrophy; and R124H from the other two families with Avellino corneal dystrophy. CONCLUSION: The above study results show that the amino acids R124 and R555, if their genetic codes result from the mutations, play an important role in the pathogenesis of autosomal dominant corneal dystrophy of Chinese patients, and the molecular genetic analysis can improve the accuracy of diagnosing corneal dystrophy. In China, the mutation R555Q found in the family with Thiel-Behnke corneal dystrophy is reported for the first time.