No evidence of association between GT/CA-repeat polymorphism in the GLC1A gene promoter and primary open-angle or exfoliation glaucoma.

PURPOSE To investigate whether variants of the polymorphic GT/CA-repeat in the regulatory sequences of the gene for GLC1A are associated with glaucoma. Mutations in the protein coding region of this gene are known to cause juvenile autosomal dominant glaucoma and are also found in a subset of cases with primary open-angle glaucoma (POAG). METHODS Samples were collected from 197 patients with exfoliation glaucoma and 157 patients with POAG as well as from 92 healthy blood donors. The variable repeat located 342 base pairs upstream of the translational initiation site, was analysed by polymerase chain reaction (PCR) and detected on an ABI 377 DNA sequencer. RESULTS Five alleles were detected, ranging in size from 13 to 17 repeat units, the most common of which was 14 repeat units. This was present in 63.7%, 66.6% and 61.4% of the two cohorts of cases and the control group, respectively. There was no significant difference in the distribution of the alleles between the control group and the two patient groups, respectively. CONCLUSION The present investigation provides no evidence that the variable repeat located in the regulatory sequences of the glaucoma gene GLC1A is associated with the risk of developing POAG or exfoliation glaucoma.