Association of DRD2 (rs 1799732), ANKK1 (rs1800497), DAT (rs28363170), DRD4 (exon 3 - VNTR) gene polymorphisms in the context of relapses in therapy.

Abstract Introduction: Disorders in the field of reward system neurotransmission are mentioned as one of the most important causes of addiction. Genetic variation is assigned a special role. The literature on the subject mentions primarily the genes of dopamine neurotransmission: DAT (dopamine transporter), DRD2 (dopamine receptor D2), DRD4 (dopamine receptor D4). However, so far there are few literature reports on these genes in the context of innovators in addiction therapy. The aim: Analysis of the relationship between the variability of specific polymorphisms in the DRD2 (rs1799732), ANKK1 (rs1800497), DAT (rs28363170), DRD4 (exon 3 - VNTR) genes with the occurrence of relapses in people addicted to psychoactive substances. Material and methods: The research was carried out on a group of 301 people addicted to psychoactive substances staying in an addiction therapy center in Lubuskie and Zachodniopomorskie voivodships in Poland. The control group consisted of 301 people with no diagnosed addiction to psychoactive substances nor mental disorders. The study of polymorphisms DRD2 (rs 1799732), ANKK1 (rs1800497) was performed by real-time PCR method; whereas DAT (rs28363170), DRD4 (exon 3 - VNTR) was genotyped by PCR and the amplified products were visualized using ethidium bromide stained gel electrophoresis (3% agarose) and UV photography. Results: This study showed that in addicts genotype frequencies of the VNTR polymorphism in the third exon of human DRD4 were as follow: S/L in 33.55%, S/S - 63.12% and L/L 3.32%; while in the control group S/L - 32.56%, S/S - 58.8 % and L/L - 8.6% (χ2 = 7.617, p = 0.022). Significant differences in the frequency of DRD2 gene polymorphism rs1799732 were observed (frequency of alleles; χ2 = 5.48, p = 0.0192) and DRD4 VNTR polymorphism (χ2 = 7.687, p = 0.021) between the addicted to psychoactive substances who have a one-time stay in an inpatient treatment center and the control group.