Methylenetetraydrofolate Reductase Gene Polymorphisms In Saudi Patients with Schizophrenia

Background: Schizophrenia is an often debilitating mental illness that affects approximately 1% of the population. Like most psychiatric disorders, it is a complex disorder that cannot be explained by a single genetic or environmental factor. Subjects and Methods: The present study is a case controlled study involving 79 patients fulfilling the ICD-10 criteria of schizophrenia and 82 healthy controls. Patients were interviewed by Diagnostic Interview for Genetic Studies (DIGS/V4.0), Positive and Negative Symptoms Scale (PANSS) and World Health Organization Disability Assessment Schedule (version 2.0) (WHO/ DAS II). All patients and controls were screened for MTHFR 677C T, 1982A C gene polymorphisms using the Real-Time PCR technique. Results: Frequencies of all genetic variants of MTHFR 677 C T and MTHFR 677 A C did not show a significant difference comparing cases to controls (p 0.05). Comparing the frequencies of genetic variants in cases having positive parental consanguinity, family history of schizophrenia or other mental illnesses to negative ones showed also non-significant results (p 0.05). Stratified analysis related to severity scores and associated clinical illnesses showed that cases having the MTHFR 677CC genotype had a higher frequency of severe dysfunction of DAS domain 1 and 6 (p=0.002 and p=0.0 respectively), while cases having the MTHFR 1982 AA genotype showed a higher frequency of severe dysfunction of the DAS domain 1 (p=0.04). Conclusion: Polymorphisms related to MTHFR 677C T, 1982A C were not associated with the susceptibility to schizophrenia among Saudi cases. However, MTHFR 677CC and MTHFR 1982 AA were associated with severe dysfunction of the cognitive function and social interaction.