Frequency evaluation of the genetic variant LCT RS4988235 (-13910 c>t), associated with lactose intolerance, in the Russian Federation

Most published studies of the prevalence of genetic predisposition to lactose intolerance in Russia have limitations, which makes it difficult to provide a complete assessment for Russia as a whole. Moreover, no comparison with the neighboring countries was performed. The aim of this work was to analyze the frequency of the LCT gene rs4988235 regulatory region variant associated with lactose intolerance in Russian regions and in some neighboring countries. As a material, buccal epithelium of 40,111 investigated subjects was used. Genotyping was performed using a real-time polymerase chain reaction with hybridization-fluorescence signal detection. The frequency of C allele associated with lactose intolerance was 67.73 ± 0.03 % on average. The prevalence of the CC genotype in Russia averaged 46.1 %; CT, 34.22 %; ТТ, 10.66 %, significantly different from European and Asian populations. The maximum frequency of the C allele was found in Yakutia (84.0% ± 0.6 %); the minimum (54.4 ± 0.7 %), in the Vladimir region. A reliable moderate correlation was found between the prevalence of the T allele and the proportion of the East Slavic population in Russian regions. The frequency of the C allele in Belarus (67.8 ± 0.4 %) and Ukraine (68.7 ± 0.3 %) is comparable with the same for Russia; in Armenia (86.4 ± 1.3 %), Georgia (87.3 ± 1.0 %), Kazakhstan (82.1 ± 0.1 %), Kyrgyzstan (81.9 ± 0.6 %) and Uzbekistan (86.4 ± 0.7 %), significantly higher than in Russia. Data concerning the frequency of rs4988235 in Russia regions were obtained from a large all-Russian population. Dis-covered similarities and differences are evidently related to the ethnic composition of Russia regions and neighboring countries.