Abstract
Purpose: To investigate whether the g.4760C > T mutation in the catalase gene (CAT) is a risk factor for primary open angle glaucoma (POAG) in the Saudi population.
Methods: A cohort of 225 unrelated POAG patients and 403 unrelated control subjects from Saudi Arabia were genotyped for a single nucleotide polymorphism (SNP; rs1001179; g.4760C > T) in the CAT gene utilizing Taq-Man® assay. The association between mutant genotypes and various clinical indices important for POAG was also investigated.
Results: The distribution of different genotypes was comparable between both study groups. The genotype "C/C" was predominant among cases; 169 (75.1%) as well as among the controls; 289 (71.7%). As for the heterozygous mutated genotype "C/T", it was present in 52 (23.1%) of cases and 103 (25.6%) of controls, where the homozygous fully mutated genotype was present in only 4 (1.8%) of cases and 11 (2.7%) of the controls. The distribution of mutant allele was similar in both study groups (p = 0.218). Interestingly, there was a trend of association between the type of the mutation (homozygous versus heterozygous) and three clinical parameters important for predicting the severity of the disease. These parameters include mean age of onset, mean level of intraocular pressure (IOP) and mean months of duration of encountering glaucoma.
Conclusions: There were no statistically significant differences between cases and controls in terms of the different genotype distribution. This mutation is possibly associated with various clinical indices important for POAG and thus may be used as a parameter for assessing POAG severity, at least in this population.