Background: 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 a Chinese family affected by granular corneal dystrophy (GCD).
Methods: Family history and phenotypic data were recorded. The diagnosis of GCD was made on the basis of clinical evaluation. The genomic DNA was extracted from peripheral blood leukocytes. All the exons and flanking intron-exon boundary sequences of TGFbetaI were amplified by polymerase chain reaction (PCR) and screened for mutation by direct DNA sequencing.
Results: A heterozygous C to T transition at nucleotide c.1663 (CGG to TGG R555W) of TGFbetaI gene was present in two affected members but was absent in the rest of the family members.
Conclusion: A recurrent pathogenic R555W of TGFbetaI gene mutation is identified, which appears to be the predominant mutations causing GCD in different populations.