MTHFR and Alzheimer disease: Wakutani and co-workers [71] investigated MTHFR haplotypes generated by the combinations of three polymorphisms, 677C>T (Ala222Val), 1298A>C (Glu429Ala), and 1793A>G (Arg594Gln), in AD subjects and controls, suggesting that the haplotype 677C/1298C/1793G could be protective against the development of AD [71].