Plasma homocysteine and the methylenetetra-hydrofolate reductase C677T gene variant: lack of association with schizophrenia

DISTURBANCES in methyl-carbon metabolism, which result in hyperhomocysteine mia, have been associated with schizophrenia. Homozygosity for the T677 all ele of the methylenetetrahydrofolate reductase (MTHFR) gene, which encodes for a thermolabile enzyme associated with hyperhomocysteinemia, has been fo und to be increased in schizophrenic patients. We have investigated whether plasma homocysteine concentration and the frequency of C677T MTHFR variant were increased in schizophrenic inpatients of a psychiatric hospital (n = 210) compared with controls (n = 218). There were no significant difference s in plasma homocysteine concentrations between the schizophrenia and the c ontrol group. The distributions of T allele and TT genotype frequencies wer e similar in both groups (40% and 15%). These results show that impaired ho mocysteine metabolism is unlikely in schizophrenia. NeuroReport 10:2035-203 8 (C) 1999 Lippincott Williams & Wilkins.