There has not yet been a meta-analysis, but almost all studies have shown that the MTHFR C677T genotype may be a maternal risk factor for CHD in children with DS, particularly if the mothers did not consume folic acid during the periconceptional period (Brandalize et al., 2009; Elsayed et al., 2014). The gene discussed is MTHFR; the disease is coronary artery disorder.