High homocysteine levels and mutations in the genes that regulate it have been found in bipolar, depressive and schizophrenic patients. Therefore, Permoda-Osip et al (2014) wished to understand the correlation between bipolar mood disorder and the mutations in genes that encode MTHFR, CBS, MTR and MTRR enzymes. 120 bipolar patients and 167 healthy controls were screened for the presence of mutations in the MTHFR C677T + A1298C, CBS T833C, MTR A2756G and MTRR A66G genes. enzymes. Overall, a mutation of the T833C gene in the CBS pathway was found to be associated with bipolar, the first evidence of its kind reveal this link.