MTHFR and isolated spina bifida: Low intake of folate during pregnancy and a common genetic variant in folate metabolism (methylenetetrahydrofolate reductase (MTHFR), 677C > T, present at ~15% homozygosity in Caucasians) are associated with an increased risk of neural tube defects (NTD) and other neurodevelopmental disorders (ND) such as autism spectrum disorder (ASD) and schizophrenia [2,3].