Purpose: Determination of the gene causing Thiel-Behnke Corneal Dystrophy (CDB2) would have important clinical implications. Previous studies in our laboratory have suggested that the COL17A1 gene may be the cause of Thiel-Behnke Corneal Dystrophy (CDB2) on Chromosome 10q23-q25.
Methods: We evaluated a five-generation family with CDB2 mapped to chromosome 10. Many of these family members were diagnosed by slit-lamp microscopy. In addition, genomic DNA was isolated and purified from peripheral blood samples. The COL17A1 gene was screened for possible disease causing mutations by PCR and DNA sequencing analysis.
Results: No disease-causing mutations were found in any of the 56 exons of the COL17A1 gene or in any of the flanking intron/exon junctions.
Conclusions: Mutations in the coding sequence of the human collagen XVII (COL17A1) gene are not the cause of CDB2.