Polymorphism rs10483727 in the SIX1/SIX6 Gene Locus Is a Risk Factor for Primary Open Angle Glaucoma in a Saudi Cohort

Aims: Variant rs10483727 in the SIX1/SIX6 locus has been significantly associated with primary open angle glaucoma (POAG) in multiple ethnic groups. We conducted a case-control study to investigate the association between this variant and POAG in a Saudi cohort. Materials and Methods: Polymorphism rs10483727 was genotyped by using a TaqMan((R)) assay in 186 subjects comprising 92 unrelated POAG cases and 94 controls all of Saudi origin. Results: The C allele frequency was 0.33 and 0.45 among POAG cases and controls, respectively (odds ratio [OR]=0.58, 95% confidence interval [CI]=0.38-0.89; p=0.013), suggesting a protective effect; and the T allele was associated with increased susceptibility to POAG (OR=1.7, 95% CI=1.11-2.58; p=0.013). Genotype distribution was also significantly associated with POAG ((2)=6.41, df=2, p=0.041). Endophenotype traits such as intraocular pressure and cup/disk ratio did not show any significant genotype distribution in POAG cases. A binary logistic regression analysis used to evaluate the effects of age, gender, and genotype on the likelihood of having POAG showed that genotype distribution (p=0.012) significantly affected the disease outcome as compared with age (p=0.055) and sex (p=0.432). Conclusion: The T allele of the rs10483727 polymorphism is an independent significant risk factor for POAG in the Saudi population.