RESUMEN
<p><b>OBJECTIVE</b>To investigate the effect of MTHFR gene on schizophrenia and its cognitive function.</p><p><b>METHODS</b>We recruited 254 schizophrenia patients with stable condition, 339 healthy controls for genetic analysis and 72 healthy controls for cognitive evaluation. The repeatable battery for the assessment of neuropsychological status (RBANS) was used for cognitive measurement. PCR-RFLP technique was carried out to genotype 677C/T polymorphism.</p><p><b>RESULTS</b>There were no significant differences in genotypic or allelic frequencies of the 677C/T polymorphism between the case and control groups (P> 0.05). In the RBANS, patients had higher scores of immediate memory, visuospatial skill, language, attention, delayed memory and total scores than healthy controls (P< 0.01); Patients with different genotypes of 677C/T polymorphism had significant differences in the scores of immediate memory, attention and total scores (P< 0.05).</p><p><b>CONCLUSION</b>Our results did not provide evidence for MTHFR gene conferring susceptibility to schizophrenia. However, there was a significant association between the MTHFR gene and cognitive impairment in patients with schizophrenia, especially in immediate memory and attention.</p>