title: Family-based association study between bipolar disorder and DRD2, DRD4, DAT, and SERT in Sardinia.
abstract: Association analysis of candidate genes may represent a strategy for clarifying the genetic components involved in bipolar disorder. Polymorphism at dopamine receptor genes DRD2, DRD4, and dopamine and serotonin transporter genes (DAT, SERT) has been used in previous association studies. Some authors have reported positive association between certain alleles and bipolar disorder, using the case-control design. In this family-based association study of DRD2, DRD4, DAT, and SERT, the distribution of parental nontransmitted alleles was compared with that of alleles transmitted to 53 Sardinian probands suffering from bipolar disorder. The transmission disequilibrium test (TDT) was used to detect any disproportionate transmission of alleles by heterozygous parents to affected children. No differences were found between the allele distribution of polymorphisms at DRD2, DRD4, DAT, and SERT in probands and parental nontransmitted chromosomes. TDT did not reveal any difference between transmitted and nontransmitted alleles. Our results do not support the hypothesis of a role for DRD2, DRD4, DAT, or SERT in bipolar disorder. Previously reported positive associations between DRD2 or SERT and bipolar disorder were conceivably due to stratification dependent on the case-control design, even though our sample might have failed to detect small associations due to limited power.
authors.affiliation: Center of Clinical Psychopharmacology, Department of Neurosciences "B.B. Brodie," University of Cagliari, Cagliari, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Bocchetta
authors.forename: M P
authors.initials: MP
authors.lastname: Piccardi
authors.forename: M A
authors.initials: MA
authors.lastname: Palmas
authors.forename: C
authors.initials: C
authors.lastname: Chillotti
authors.forename: A
authors.initials: A
authors.lastname: Oi
authors.forename: M
authors.initials: M
authors.lastname: Del Zompo
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000483:Alleles; D001714:Bipolar Disorder / Q000235:genetics*; D002352:Carrier Proteins / Q000235:genetics*; D050483:Dopamine Plasma Membrane Transport Proteins; D005260:Female; D005838:Genotype; D006801:Humans; D007558:Italy; D015810:Linkage Disequilibrium; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics*; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; D010290:Parents; D011110:Polymorphism, Genetic; D017448:Receptors, Dopamine D2 / Q000235:genetics*; D050638:Receptors, Dopamine D4; D050486:Serotonin Plasma Membrane Transport Proteins
chemical_list: D002352:Carrier Proteins; C493599:DRD4 protein, human; D050483:Dopamine Plasma Membrane Transport Proteins; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; D017448:Receptors, Dopamine D2; C493214:SLC6A3 protein, human; C493230:SLC6A4 protein, human; D050486:Serotonin Plasma Membrane Transport Proteins; D050638:Receptors, Dopamine D4