Abstract
Background: Down syndrome (DS) is a complex genetic disease that is caused by having three copies of chromosome 21. A possible association between polymorphisms in maternal folate metabolism genes and DS has been evaluated. Objectives: It was aimed to first investigate the influence of C677T and A1298C polymorphisms in the methylenetetrahydrofolate reductase gene (MTHFR) and plasma homocysteine (Hcy) on the maternal risk for DS in the southwest of Iran. Methods: The MTHFR C677T and A1298C polymorphisms were genotyped using restriction fragment length polymorphism and Sanger sequencing, respectively. Allele and genotype frequencies and the dominant model of the MTHFR C677T and A1298C polymorphisms were evaluated in 80 mothers of children with DS and 80 control mothers. Eventually, the ELISA test was used to compare the concentration of plasma Hcy in both groups. Results: A significant association was observed in the 677T and 1298C alleles between the mothers of DS and control groups (P = 0.00077 and P = 0.01248, respectively). Further, the median concentrations of Hcy were significantly higher in mothers with DS babies compared to the control group (P < 0.05). Conclusions: There was an association between MTHFR C677T, A1298C, and plasma Hcy concentrations as the maternal risk of mothers with DS children.