Allele and genotype frequencies of serotonin and dopamine transporter and receptor polymorphisms in a Norwegian population.

Polymorphisms in genes coding for dopaminergic and serotonergic receptors and transporters have been associated with the clinical effects and adverse drug reactionsof antipsychotic and antidepressant drugs. The objective of this study was to investigate the frequency and combinations of common polymorphisms in the dopamine transporter(DAT1), dopamine D2 receptor (DRD2), dopamine D3 receptor (DRD3), serotonin transporter(5HTT), and serotonin 2A receptor (5HTR2A) genes in a Norwegianpopulation. To determine the background frequency in the population, 250 blood samples were consecutively collected from healthy Norwegianblood donors (125 men and 125 women; mean age: 48±11 years). Samples were tested for DAT1 VNTR, DRD2 Taq1A, DRD3 Ser9Gly, 5HTTLPR, and four polymorphisms (102 T>C, His452Tyr, 516 C>T, and Thr25Asn) in the 5HTR2A, using polymerase chain reactionand real-time polymerase chain reaction. We observed the frequency of the nine-repeat allele of DAT1 VNTR polymorphism as 20% (95% confidence inte...