Adrenergic alpha 2C receptor genomic organization: Association study in adult ADHD

Attention deficit hyperactivity disorder (ADHD) is a chronic psychiatric condition in children and follow up studies have indicated that one to two thirds of patients continue to suffer from ADHD during late adolescence and adulthood. Pharmacological interventions, such as the new selective noradrenergic reuptake inhibitor, atomoxetine, suggest the adrenergic system as candidate in ADHD. We examined for the presence of linkage disequilibrium between the alpha 2C adrenergic receptor (ADRA2C) microsatellite polymorphism upstream of the ADRA2C gene and adult ADHD in a sample of nuclear families. We also present new information on the genomic organization of the ADRA2C locus. The microsatellite polymorphism was typed in 128 small families and analyzed using the Transmission Disequilibrium Test (TDT). There was no preferential transmission of any allele. These findings exclude a strong effect of this ADRA2C marker on risk for ADHD in our sample of adult proband families.