However, when MDS were stratified according to folic acid supplementation at peri-conception, the risk for DS-CHD remained significant only in those with MTHFR 677CT or TT genotype that did not take folic acid supplements (OR = 2.26; 95% CI = 1.25–4.09), but was lost in those MDS that used folic acid supplements at peri-conception (OR = 1.07; 95% CI = 0.20–5.68). The gene discussed is MTHFR; the disease is coronary artery disorder.