In this review, we not only gathered the most recent discoveries on MTHFR polymorphism and related DNA methylation in various psychiatric disorders, but also highlighted the potential relationships between MTHFR activity and implication of folate-related function in specific mental diseases.
Past analyses examining the relationship between genetic variation in the 5, 10-methylenetetrahydrofolate reductase (MTHFR) gene and psychiatric disorders have provided mixed and largely inconclusive findings.
We hypothesized that children with autism who are homozygous for the MTHFR 677 T allele (TT) and, to a lesser extent those with the CT variant, would exhibit more behavioral problems and/or more severe problematic behaviors than homozygous wild-type (CC) individuals because of difficulties in effectively converting 5,10-MTHF to 5-MTHF.
The methylenetetrahydrofolate reductase (MTHFR) gene variant C677T is suspected to be a risk factor for psychiatric disorders, but it remains uncertain whether the MTHFR C677T variant is associated with bipolar disorders.
Since a common variant of the MTHFR gene, T677(Ala), responsible for the thermolabile MTHFR with less than 50% specific MTHFR activity, has been reported, we examined whether the T677 allele is associated with psychiatric disorders in an unrelated Japanese population consisting of 297 schizophrenics, 32 patients with major depression, 40 patients with bipolar disorder, and 419 controls.