title: No evidence of association or linkage disequilibrium between polymorphisms in the 5' upstream and coding regions of the dopamine D4 receptor gene and schizophrenia in a Portuguese population.
abstract: Alterations in dopaminergic system have been implicated in the pathophysiology of this disease for many years, and this study was performed to assess the possible involvement of the dopamine D4 receptor (DRD4) gene polymorphisms either in the 5' upstream or in the coding regions, in the etiology of schizophrenia. The approach included an association study with 90 Portuguese trios by doing the analysis of the individual alleles and the haplotypes. For the polymorphisms in the 5' upstream region (-C616G and -C521T) and in the coding region (48 bp repeat) of the DRD4 gene, negative results were obtained with both haplotype relative risk (HRR) and transmission disequilibrium test (TDT), as well as transmit. These data suggest that polymorphisms (-C616G, -C521T, and 48 bp repeat) at the DRD4 gene do not have a minor effect in the susceptibility to schizophrenia in our sample.
authors.affiliation: Center for Neuroscience of Coimbra, Department of Neurochemistry, Faculty of Medicine, University of Coimbra, Coimbra, Portugal. aldachico@yahoo.com
authors.forename: Alda M
authors.initials: AM
authors.lastname: Ambrósio
authors.forename: James L
authors.initials: JL
authors.lastname: Kennedy
authors.forename: Fabio
authors.initials: F
authors.lastname: Macciardi
authors.forename: Cathy
authors.initials: C
authors.lastname: Barr
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Soares
authors.forename: Catarina R
authors.initials: CR
authors.lastname: Oliveira
authors.forename: Carlos N
authors.initials: CN
authors.lastname: Pato
mesh_terms: D000483:Alleles; D005260:Female; D006239:Haplotypes / Q000235:genetics*; D006801:Humans; D015810:Linkage Disequilibrium / Q000235:genetics*; D008297:Male; D011110:Polymorphism, Genetic / Q000235:genetics*; D011174:Portugal; D017448:Receptors, Dopamine D2 / Q000235:genetics*; D050638:Receptors, Dopamine D4; D012559:Schizophrenia / Q000235:genetics*
chemical_list: C493599:DRD4 protein, human; D017448:Receptors, Dopamine D2; D050638:Receptors, Dopamine D4