Methylenetetrahydrofolate reductase gene polymorphisms in patients with schizophrenia.

To investigate the role of methylenetetrahydrofolate reductase gene polymorphisms in schizophrenia, we analyzed the genotypes of MTHFR677 and MTHFR1298 of 130 schizophrenic patients and 226 controls, using a polymerase chain reaction restriction fragment length polymorphism method. The MTHFR T677 allele was significantly distributed (chi(2)=7.900; P=0.019), between schizophrenic cases and healthy controls. The T677T genotype was overrepresented in the schizophrenic patients (OR=2.504; 95% CI=1.276-4.915; chi(2)=7.477; P=0.006). The T677T/A1298A, and C677T/C1298C compound genotypes were greater in the schizophrenic patients (OR=3.157; 95% CI=1.522-6.545; chi(2)=10.336; P=0.001 and OR=1.744; 95% CI=0.108-28.121; chi(2)=0.158; P=0.691, respectively). The MTHFR T677 allele and T677T and T677T/A1298A genotypes are genetic risk factors for schizophrenia.