title: Gene-gene and gene-environment interaction on the risk of Parkinson's disease.
abstract: BACKGROUND
  Even with numerous studies the cause of Parkinson's disease (PD) remains elusive. It has been hypothesized that interactions between genetic and environmental factors may play an important role in the pathogenesis of PD.
  
  
  OBJECTIVE
  To examine the gene-gene and gene-environment interaction on PD risk with respect to gene polymorphism of cytochrome P450 2D6 (CYP2D6) and glutathione S-transferases pi 1 (GSTP1), organochlorine pesticides (OCPs) and metals.
  
  
  METHODS
  This study included 70 patients of PD and 100 age-matched controls. The restriction fragment length polymorphism was used for analysis of genetic polymorphism. OCPs and serum metal levels were estimated by using gas chromatography and an autoanalyser respectively.
  
  
  RESULTS
  The CYP2D6*4 mt and GSTP1 *B allelic variants were significantly associated with increase in PD risk. We found a statistically significant difference in β -hexachlorocyclohexane (β-HCH), dieldrin, 1,1-dichloro-2,2-bis(pchlorophenyl) ethylene (pp'-DDE) and copper levels between the patients and controls. We found significantly high levels of β-HCH, dieldrin and pp'-DDE in the CYP2D6*4 mt allelic variants, β-HCH and pp'-DDE in the GSTP1*B allelic variants and dieldrin in the GSTP1*C allelic variants when comparing CYP2D6*4 non-mt, GSTP1 non-*B and GSTP1 non-*C allelic variants in patients of PD respectively.
  
  
  CONCLUSIONS
  This study demonstrates that the CYP2D6*4 and GSTP1 genes may be considered as candidate genes for PD and they may also interact with β- HCH, dieldrin and pp'-DDE to influence the risk for PD.
authors.forename: Neeraj Kumar
authors.initials: NK
authors.lastname: Singh
authors.forename: Basu Dev
authors.initials: BD
authors.lastname: Banerjee
authors.forename: Kiran
authors.initials: K
authors.lastname: Bala
authors.forename: Mitrabasu
authors.initials: M
authors.lastname: Chhillar
authors.affiliation: Head, Department of Neurochemistry, Institute of Human Behaviour and Allied Sciences, Dilshad Garden, Delhi-110095, India. nlmchhillar@yahoo.co.in.
authors.forename: Neelam
authors.initials: N
authors.lastname: Chhillar
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D019389:Cytochrome P-450 CYP2D6 / Q000235:genetics / Q000378:metabolism; D004843:Epistasis, Genetic; D005260:Female; D005787:Gene Frequency; D059647:Gene-Environment Interaction; D020022:Genetic Predisposition to Disease; D051549:Glutathione S-Transferase pi / Q000235:genetics / Q000378:metabolism; D006801:Humans; D006843:Hydrocarbons, Chlorinated / Q000009:adverse effects / Q000097:blood; D008297:Male; D008670:Metals / Q000009:adverse effects / Q000097:blood; D008875:Middle Aged; D010300:Parkinson Disease / Q000097:blood / Q000175:diagnosis / Q000201:enzymology / Q000235:genetics*; D010302:Parkinson Disease, Secondary / Q000097:blood / Q000139:chemically induced / Q000175:diagnosis / Q000201:enzymology / Q000235:genetics*; D010575:Pesticides / Q000009:adverse effects / Q000097:blood; D010641:Phenotype; D012307:Risk Factors
chemical_list: D006843:Hydrocarbons, Chlorinated; D008670:Metals; D010575:Pesticides; D019389:Cytochrome P-450 CYP2D6; C496556:GSTP1 protein, human; D051549:Glutathione S-Transferase pi