International Union for Circumpolar Health Ministry of Public Health and Social Development of RF Russian Academy of Medical Sciences Siberian Branch of Russian Academy of Medical Sciences Siberian Branch of Russian Academy of Sciences Medical Polar Fund “Science” The Northern Forum

Abstracts

Genetics, demography, anthropology

BACKGROUND: The dopamine transporter (DAT1 or SLC6A3) plays the important role in neurotransmission, serves as a critical regulator of dopaminergic neurotransmission. DAT1 is the member of a family of Na+/Cl- dependent transmembrane transport proteins. It is an integral membrane protein and regulates the reuptake of released dopamine back into presynaptic terminals after its synaptic release. Human DAT1 gene is 52.6 kb pairs in length and is located on chromosome 5р15.33. It contains 15 exons. The variable number of tandem repeats (VNTR) was revealed in its 3 '-untranslated region (3’-UTR), which is composed of a 40-bp core sequence. VNTR ranges from 3 to 13 copies in a wide spectrum of population samples. The DAT1 VNTR is a functional polymorphism and DAT1 activity depends on number copies of repeats (VanNess S. et al., 2005). Associations between the VNTR polymorphism and attention-deficit/hyperactivity disorder, alcoholism, cigarette smoking, schizophrenia and other behavior problems was shown.

OBJECTIVE: To describe distribution of the VNTR polymorphism in the 3’-UTR DAT1gene in Russian, Yakut and Khant populations, with the purpose of future use for genetic testing susceptibility to behavioral deviations in these ethnic groups.

MATERIALS and METHODS: VNTR polymorphism of the DAT1 gene was investigated by polymerase chain reaction (PCR) method and electrophoresis in 3 % agarose gele in three Russian populations: Tomsk city (n=125). Seversk city (n=219) and Kargala village (n=158) of Tomsk area, in three Yakut populations: Dypsja (n=112), Bjady (n=155) and Cheriktey (n=126) villages of Ust’-Aldansky ulus in Republic of Sakha (Yakutia), and also in Khanty population of Russkinskaya village (n=129) of the Surgut region in Khanty-Mansy Autonomous District. An estimation of difference in genotype frequencies was carried out with the Maximum-Likelihood χ2 statistics.

RESULTS: The genotype frequencies obeyed the Hardy-Weinberg equilibrium in all investigated populations. No interpopulation difference was revealed in genotype frequencies in Russian and Yakut ethnic groups. Interethnic difference in genotype frequencies were found out: Russians (n=502) - Yakuts (n=393, P <10**-5); Russians - Khanty (Р=2*10**-5) and Yakuts – Khanty (P <10**-5). The allele frequencies were: DAT1*7 0.1, 2.4 and 3.5 %; DAT1*9 21.5, 5.5 and 18.6 %; DAT1*10 78.4, 91.7 and 77.9 %; DAT1*11 0.0, 0.4 and 0.0 % for Russian, Yakut and Khant populations, respectively.

CONCLUSION: Our results indicate an ethnic peculiarity of the investigated populations, and high frequency of allele with ten copies of repeats in Yakuts (91.7 %), presumably, assumed a marked founder effect in this population.

Note. Abstracts are published in author's edition

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Last update: 06-Jul-2012 (11:52:05)