Polymorphism of the <i>MAOA</i> Gene (rs1137070) and Internet Addiction in Adolescents

Abstract

Monoamine oxidase A (MAOA) catalyzes the degradation of norepinephrine, dopamine, and serotonin, i.e. neurotransmitters involved in the pathogenesis of pathological addictions, including internet addiction (IA). Gene MAOA has been actively studied in terms of genetic predisposition to the development of aggressive behavior potentially involved in the formation of IA. The study included 602 adolescents (9–18 years old, mean age = 14.6, SD 1.7) from the Angara-Yenisei macroregion (Russians n = 329, Tuvans n = 158, Khakasses n = 158). The type of IA was assessed according to the Chen scale (Chen Internet Addiction Scale, CIAS), gene polymorphism was detected using real-time PCR. The distribution of the TT genotype of MAOA rs1137070 polymorphism associated with low activity of the monoamine oxidase A enzyme and aggressive behavior affected by IA, was found to be significantly higher in Tuvan adolescents compared with Russians (31.1/21.2% p = = 0.02). Pathological internet addiction (more than 65 points by Chen scale) often observed among Khakass adolescents compared to Russian (26.4/15.5%, p = 0.03). Thus, the allelic variant T of MAOA rs1137070 polymorphism appears to be potential marker for dependent and aggressive behavior to form, Asian representatives being more susceptible to the development of pathological addictions than Caucasian populations.