title: Lack of association between polymorphisms of dopamine receptors, type D2, and bipolar affective illness in a Polish population.
abstract: BACKGROUND
  Biochemical abnormalities are thought to be important factors causing bipolar disorder. Several lines of evidence suggest dopamine may play a role in its etiology, e.g. depressive syndrome is frequently encountered in subjects affected by Parkinson's disease, where dopamine depletion is observed. Thus the genes of the dopaminergic system are good candidates for studies on bipolar disorder. In the present study, we investigated polymorphisms of dopamine receptors, type D2, including the dopamine receptors D2, D3 and D4.
  
  
  METHODS
  Polish bipolar patients (n=339) and control subjects (n=366) were analyzed for three dopamine receptor gene polymorphisms: dopamine receptor D2 (DRD2) 141 ins/del, dopamine receptor D3 (DRD3) Ser9Gly, and dopamine receptor D4 (DRD4) 521 C/T.
  
  
  RESULTS
  Allele and genotype frequencies did not differ significantly among patients and controls. We did not obtain any significant association between the studied polymorphisms and bipolar disorder.
  
  
  CONCLUSIONS
  The results suggests that the studied gene variants of type D2 dopamine receptors are not promising candidate genes for bipolar affective illness. We did not consider the family history of the examined subjects, and also the control group was not psychiatrically screened, which may contribute to the lack of significant results.
authors.affiliation: Department of Adult Psychiatry, University of Medical Sciences, Poznań, Poland. a.l.rodziewicz@wp.pl
authors.forename: Anna
authors.initials: A
authors.lastname: Leszczyńska-Rodziewicz
authors.forename: Joanna
authors.initials: J
authors.lastname: Hauser
authors.forename: Monika
authors.initials: M
authors.lastname: Dmitrzak-Weglarz
authors.forename: Maria
authors.initials: M
authors.lastname: Skibińka
authors.forename: Piotr
authors.initials: P
authors.lastname: Czerski
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Zakrzewska
authors.forename: Magdalena
authors.initials: M
authors.lastname: Kosmowska
authors.forename: Janusz K
authors.initials: JK
authors.lastname: Rybakowski
mesh_terms: D000293:Adolescent; D000328:Adult; D001714:Bipolar Disorder / Q000235:genetics*; D005260:Female; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D008297:Male; D011044:Poland; D011110:Polymorphism, Genetic; D017448:Receptors, Dopamine D2 / Q000235:genetics*; D050637:Receptors, Dopamine D3; D050638:Receptors, Dopamine D4; D012016:Reference Values; D017384:Sequence Deletion
chemical_list: C493593:DRD3 protein, human; C493599:DRD4 protein, human; D017448:Receptors, Dopamine D2; D050637:Receptors, Dopamine D3; D050638:Receptors, Dopamine D4