Association Between The CPG Island Methylation Status Of Promoter Of Methylenetetrahydrofolate Reductase Gene And Schizophrenia

Backgroud Schizophrenia is one of the common mental diseases, whose incidence is about1percent in the world. Methylenetetrahydrofolate reductase (MTHFR) gene is one of the candidate genes for schizophrenia. Previous studies have demonstrated that schizophrenia may have a relationship with the mutation of MTHFR gene and the metabolism disorder of Hcy and folic acid. Presently, relevant researches mainly focus on the two polymorphic loci (C667T and A1298C) of MTHFR gene. The CpG island methylation status of promoter of MTHFR gene can affect its expression, thus the activity of MTHFR may be affected, which can finally lead to the occurrence of schizophrenia. However, to date, there are still no related studies on this assumption in the world.Objective To investigate the association between the CpG island methylation status of promoter of MTHFR gene and patients with schizophreniaMethods20patients with schizophrenia and20healthy subjects were selected for this study. After the sodium bisulfate treatment of all the collected blood samples, methylation specific PCR (MSP) and bisulfate sequencing PCR (BSP) were respectively used to detect the the CpG island methylation status of promoter of MTHFR gene. Moreover, the Hcy level was also detected for all the subjects in the serum.Results Three sites are partially methylated in the CpG islands of promoter of MTHFR gene (69,80and129locus, respectively). The incidence of partially methylated CpG islands in the promoter region of MTHFR gene (40%vs.20%) is higher in patient group than that in control group, but there is no significant difference between the two groups (P>0.05). The Hey level in the serum (26.29±9.36umol/L vs.23.66±5.27umol/L) is also higher in patient group than in control group, and there is a significant difference between the two groups (P=0.044). In addition, no significant difference is detected regarding the CpG island methylation status of promoter of MTHFR gene and the Hcy level in the serum with age and gender (bothP>0.05).Conclusions The69,80and129loci are partially methylated in the CpG island of promoter of MTHFR gene. No association between the CpG islands methylation status of promoter of MTHFR gene and schizophrenia was found. There may be no association between the elevated blood Hcy level of patients with schizophrenia and the change of CpG island methylation status of promoter of MTHFR gene. No difference was detected regarding the CpG island methylation status of promoter of MTHFR gene and the blood Hcy level with age and gender.