title: Analysis of association between dopamine receptor genes' methylation and their expression profile with the risk of schizophrenia.
abstract: OBJECTIVE
  Schizophrenia (SCZ) is a type of psychotic disorder that affects ~1% of the population. Dopamine is one of the major neurotransmitters in the brain and its receptors are associated with a number of psychotic disorders, including SCZ. The aims of the present study were to analyze methylation and the expression profile of dopamine receptor DRD1, DRD2, DRD4, and DRD5 genes in patients with SCZ.
  
  
  METHODS
  Promoter methylation of DRD1, DRD2, DRD4, and DRD5 genes was assayed by a methylation-specific PCR in blood samples obtained from 80 SCZ cases and 71 healthy controls. Also, we investigated DRD1, DRD2, DRD4, and DRD5 mRNA levels using real-time reverse transcription PCR in 34 blood samples of healthy controls and cases.
  
  
  RESULTS
  Promoter methylation of DRD4, DRD5, and DRD2 genes was statistically different in cases compared with healthy controls. The mRNA expression level results also showed statistically significant differences (P<0.0001) between cases and healthy controls for the DRD2, DRD4, and DRD5 genes, but not for DRD1.
  
  
  CONCLUSIONS
  Analyses of DRD genes' methylation have highlighted the fact that the DRD gene network, overall, is actively involved in the increased risk of SCZ.
authors.affiliation: Department of Biology, University of Sistan and Baluchestan, Zahedan, Iran. dor_kordi@yahoo.com
authors.forename: Dor Mohammad
authors.initials: DM
authors.lastname: Kordi-Tamandani
authors.forename: Roya
authors.initials: R
authors.lastname: Sahranavard
authors.forename: Adam
authors.initials: A
authors.lastname: Torkamanzehi
mesh_terms: D016022:Case-Control Studies; D019175:DNA Methylation / Q000235:genetics*; D020869:Gene Expression Profiling; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D006801:Humans; D011401:Promoter Regions, Genetic / Q000235:genetics; D011954:Receptors, Dopamine / Q000235:genetics*; D012307:Risk Factors; D012559:Schizophrenia / Q000235:genetics*
chemical_list: D011954:Receptors, Dopamine