MTHFR and metabolic syndrome: Moreover, genetic studies which found MetS, schizophrenia, and mood disorders all to share the association with genes encoding for α-ketoglutarate-dependent dioxygenase (FTO), an mRNA demethylase, methylenetetrahydrofolate reductase (MTHFR), the rate-limiting enzyme in the methyl cycle, and leptin (5, 11, 12) further support the hypothesis of a partially shared pathogenesis of MetS and psychiatric diseases.