Homozygous polymorphism of the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene and resultant hyperhomocysteinaemia have been established as an independent risk factor for vascular diseases. There are evidences that vascular abnormalities are involved in the pathogenesis and progression of normal-tension glaucoma (NTG). In the present study, we were to find out the associations between 677C>T and 1298A>C polymorphisms of the MTHFR gene and NTG.
This was a retrospective, case-controlled study enrolling 78 NTG patients and 100 controls. DNA from peripheral blood lymphocytes was extracted and the genotypes of polymorphisms (677C>T and 1298A>C) in the MTHFR gene were determined using PCR followed by restriction enzyme digestion. The frequencies of the polymorphic genotypes in the patients with NTG and controls were compared.
The frequencies of the polymorphisms of the MTHFR gene (677C>T and 1298A>C) in the NTG patients were not significantly different from those of controls. But the younger NTG patients (age at diagnosis < or = 45 years) showed significantly higher prevalence of 677C>T polymorphism than the older NTG patients (age at diagnosis > 45 years) (TT genotype, 38.9 vs 11.9%, P=0.006, OR=4.71, 95% CI=1.49-14.9) and than the younger control subgroup (TT genotype, 38.9 vs 6.1%, P=0.001, OR=9.86, 95% CI=2.23-42.4).
The 677C>T polymorphism was significantly associated with NTG in the younger patients, while 1298A>C polymorphism was not. This suggests that 677C>T polymorphism of the MTHFR gene can be a genetic risk factor of NTG in Korean population.