Purpose: To evaluate the association of the myocilin gene promoter variant -1000C>G (MYOC.mt1) with primary open angle glaucoma (POAG) and its possible role on the phenotype and the severity of glaucoma in Turkish patients.
Methods: Eighty eight POAG patients and 123 healthy subjects were included in the study. All subjects were genotyped by PCR-RFLP. Allele and genotype frequencies between healthy subjects and glaucoma patients were compared by the chi2 test. The age at diagnosis, the age at inclusion, the maximum IOP at diagnosis and the number of antiglaucomatous medications were compared between MYOC.mt1 carriers and non-carriers using the Student's t-test; C/D ratio, mean deviation (MD), and pattern standard deviation values were compared with the Mann-Whitney U-test. Statistical significance was defined as p<0.05.
Results: MYOC.mt1 genotype and allele frequencies did not differ in POAG and healthy subjects (p=0.204 and p=0.083, respectively). In the control group, 17.1% of the subjects were MYOC.mt1 carriers, while 27.3% of the POAG patients were MYOC.mt1 carriers (p=0.107). The odds ratio for CG was 1.859 (95% CI: 0.9-3.7; p=0.084) and for GG 1.594 (95% CI: 0.31-8.13; p=0.575). The phenotype variables were quite similar in MYOC.mt1 carriers and non-carriers. Gender by itself or with the MYOC.mt1 did not have any effect on IOP, C/D ratio, or MD values (univariate analysis of variance, p>0.05). No significant difference was found in the distribution of genotypes between different stages of glaucoma groups (p=0.93).
Conclusions: Our results suggest that in our Turkish glaucoma patients, MYOC.mt1 is not a risk factor for the development of POAG and is not associated with the phenotype and severity of glaucoma.