title: Family-based and case-control study of DRD2, DAT, 5HTT, COMT genes polymorphisms in alcohol dependence.
abstract: The paper focuses on such candidate gene polymorphisms that alter alcoholism-related intermediate phenotypes including: dopaminergic system polymorphic variants (DRD2 -141C Ins/Del in promoter region, exon 8 and DRD2 TaqI A and DAT 40bp VNTR genes polymorphisms) that cause predisposition to severe alcoholism (haplotype Ins/G/A2); COMT Val158Met gene polymorphism related to differences in executive cognitive function and 5-HTT gene promoter polymorphism, which alters stress response and affects anxiety and dysphoria. The transmission disequilibrium test (TDT) was used in the study. One hundred Polish families with alcohol dependence were recruited. The control subjects for the case-control study were 196 ethnically and gender matched healthy individuals. It was found that DRD2 TaqIA and DAT gene polymorphisms contained statistically significant differences in allele transmission. In the homogenous subgroups of patients with early onset and with withdrawal complications a statistically significant preferential A2 allele transmission was found in DRD2 TaqIA gene polymorphism. The alleles and genotypes distribution of the investigated polymorphisms did not differ significantly between the alcoholics and the controls in the case-control study. The results confirmed the fact that the candidate genes (DRD2 and DAT) are partially responsible for the development of alcohol dependence. The results are also in agreement with the hypothesis that there are various subtypes of alcohol dependence, which differ depending on their genetic background. Meanwhile, the currently available pharmacological therapies for alcoholism treatment are effective in some alcoholics but not for all of them. Some progress has been made in elucidating pharmacogenomic responses to drugs, particularly in the context of Clonninger and Lesch typology classification system for alcoholics.
authors.affiliation: Department of Psychiatry, Pomeranian Medical University, Broniewskiego 26, 71-460 Szczecin, Poland. samoj@sci.pam.szczecin.pl <samoj@sci.pam.szczecin.pl>
authors.forename: Jerzy
authors.initials: J
authors.lastname: Samochowiec
authors.forename: Jolanta
authors.initials: J
authors.lastname: Kucharska-Mazur
authors.forename: Anna
authors.initials: A
authors.lastname: Grzywacz
authors.forename: Marcin
authors.initials: M
authors.lastname: Jabłoński
authors.forename: Hans
authors.initials: H
authors.lastname: Rommelspacher
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Samochowiec
authors.forename: Mariusz
authors.initials: M
authors.lastname: Sznabowicz
authors.forename: Jan
authors.initials: J
authors.lastname: Horodnicki
authors.forename: Leszek
authors.initials: L
authors.lastname: Sagan
authors.forename: Justyna
authors.initials: J
authors.lastname: Pełka-Wysiecka
mesh_terms: D000328:Adult; D000437:Alcoholism / Q000235:genetics*; D000483:Alleles; D016022:Case-Control Studies; D002394:Catechol O-Methyltransferase / Q000235:genetics*; D050483:Dopamine Plasma Membrane Transport Proteins / Q000235:genetics*; D005192:Family Health; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D006801:Humans; D015810:Linkage Disequilibrium; D008297:Male; D008715:Methionine / Q000235:genetics; D008875:Middle Aged; D018598:Minisatellite Repeats / Q000235:genetics; D011110:Polymorphism, Genetic; D017448:Receptors, Dopamine D2 / Q000235:genetics*; D050486:Serotonin Plasma Membrane Transport Proteins / Q000235:genetics*; D014633:Valine / Q000235:genetics
chemical_list: D050483:Dopamine Plasma Membrane Transport Proteins; D017448:Receptors, Dopamine D2; D050486:Serotonin Plasma Membrane Transport Proteins; D008715:Methionine; D002394:Catechol O-Methyltransferase; D014633:Valine