title: Association of attention-deficit disorder and the dopamine transporter gene.
abstract: Attention-deficit hyperactivity disorder (ADHD) has been shown to be familial and heritable, in previous studies. As with most psychiatric disorders, examination of pedigrees has not revealed a consistent Mendelian mode of transmission. The response of ADHD patients to medications that inhibit the dopamine transporter, including methylphenidate, amphetamine, pemoline, and bupropion, led us to consider the dopamine transporter as a primary candidate gene for ADHD. To avoid effects of population stratification and to avoid the problem of classification of relatives with other psychiatric disorders as affected or unaffected, we used the haplotype-based haplotype relative risk (HHRR) method to test for association between a VNTR polymorphism at the dopamine transporter locus (DAT1) and DSM-III-R-diagnosed ADHD (N = 49) and undifferentiated attention-deficit disorder (UADD) (N = 8) in trios composed of father, mother, and affected offspring. HHRR analysis revealed significant association between ADHD/UADD and the 480-bp DAT1 allele (chi 2 7.51, 1 df, P = .006). When cases of UADD were dropped from the analysis, similar results were found (Chi 2 7.29, 1 df, P = .007). If these findings are replicated, molecular analysis of the dopamine transporter gene may identify mutations that increase susceptibility to ADHD/UADD. Biochemical analysis of such mutations may lead to development of more effective therapeutic interventions.
authors.affiliation: Department of Psychiatry, University of Chicago, IL, USA.
authors.forename: E H
authors.initials: EH
authors.lastname: Cook
authors.forename: M A
authors.initials: MA
authors.lastname: Stein
authors.forename: M D
authors.initials: MD
authors.lastname: Krasowski
authors.forename: N J
authors.initials: NJ
authors.lastname: Cox
authors.forename: D M
authors.initials: DM
authors.lastname: Olkon
authors.forename: J E
authors.initials: JE
authors.lastname: Kieffer
authors.forename: B L
authors.initials: BL
authors.lastname: Leventhal
mesh_terms: D000293:Adolescent; D001289:Attention Deficit Disorder with Hyperactivity / Q000235:genetics*; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D050483:Dopamine Plasma Membrane Transport Proteins; D006801:Humans; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D018598:Minisatellite Repeats; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins
chemical_list: D002352:Carrier Proteins; D050483:Dopamine Plasma Membrane Transport Proteins; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; C493214:SLC6A3 protein, human