Methylenetetrahydrofolate reductase gene polymorphisms and neural tube defects epidemiology in the Slovak population.

Background: Folate deficiency is a known factor contributing to the formation of neural tube defects (NTDs). Many folate metabolism gene variants have been investigated, but only a few substantial associations have been established, the C677T polymorphism of the methylenetetrahydrofolate reductase (MTHFR) gene being one of the most significant.

Methods: We determine the MTHFR C677T and A1298C genotypes in 93 Slovak NTD patients and 290 control newborns with respect to sex and ethnicity. Furthermore, we summarize current data on the incidence and types of NTDs in Slovakia.

Results: The Slovak population frequencies of T allele and TT genotype of the C677T MTHFR gene polymorphism were 0.25 and 6.9%, respectively; similarly, those of the C allele and CC genotype of the A1298C polymorphism were 0.35 and 13.8%, respectively. No differences between the sexes and within ethnic groups were observed. In NTD patients, genotype analysis of the C677T polymorphism revealed 0.29 and 9.8% for T allele and TT genotype frequencies, respectively (p = 0.26; OR, 1.23; 95% CI, 0.84-1.81; resp. p = 0.36; OR, 1.46; 95% CI, 0.56-3.52) compared to the controls. The frequencies of C allele and CC genotype of A1298C polymorphism were 0.34 and 6.5%, respectively (p = 0.81; OR, 0.96; 95% CI, 0.66-1.38; resp. p = 0.06; OR, 0.44; 95% CI, 0.15-1.09). There were also no sex-related differences in genotypes distribution in NTD patients.

Conclusions: No significant associations between the C677T and A1298C MTHFR gene polymorphisms and NTDs and no differences between the two main ethnic groups (white-Caucasians, Roma) were found in Slovakia. The total incidence of NTDs in Slovakia is, according to the official sources, 0.53/1000, and the incidence among liveborn newborns is 0.28/1000.