Abstract
Abstract: :
Purpose: Corneal endothelial dystrophy is divided into 3 types including Fuchs’ endothelial corneal dystrophy (FECD), posterior polymorphous dystrophy (PPMD), and congenital hereditary endothelial dystrophy (CHED), and each of these groups is regarded as a disease exhibiting genetic heterogeneity. We performed random sequence and similarity search analysis of 1,000 clones from rabbit corneal endothelial cDNA library in a previous study. Collagen type VIII alpha 1 chain (COL8A1) was the most frequently observed cDNA in the library. In the present study, we screened COL8A1 mutation in 19 patients with corneal endothelial dystrophy to evaluate COL8A1 as a candidate gene for this dystrophy. Methods: Genomic DNAs were extracted from leukocytes of peripheral blood collected, with informed consent, from 19 patients. We designed primers using the latest database including human genome sequences and amplified the COL8A1 coding region from genomic DNAs of patients using a PCR method. Denaturing high performance liquid chromatography (DHPLC) with hetero duplex method was used to detect mutations, and the dye terminator method was used for sequencing. Results: None of 19 patients had a mutation in the 540 bp range of the 5’ region in exon 2. Investigation of other regions is in progress. Conclusions: Although it cannot be concluded that COL8A1 is a causal gene for corneal endothelial dystrophy from findings obtained thus far, it is considered an important candidate gene since collagen type VIII is composed of a triple helix consisting of two alpha 1 chains and one alpha 2 chain. It is necessary to increase the number of patients and advance the mutation analysis.
Keywords: cornea: endothelium • genetics • mutations