AIM:To estimate the prevalence of the lactase non-persistent genotype(C/C-13910)in a northern Russian population in accordance with ethnicity,and to evaluate self-reported milk consumption depending on lactase activity. METHODS:Blood samples for genotyping lactase activity,defining the C/T-13910 variant by polymerase chain reaction,and direct sequencing were taken from 231 medical students of Russian origin aged 17-26 years. We analyzed milk product consumption by questionnaire which was specially designed for the estimation of milk consumption and abdominal complaints. RESULTS:We found that the prevalence of the C/C-13190 genotype in the northern Russian population was 35.6%.The other genotypes nearby C/T-13910 and associated with lactase activity were not present in the study population.The consumption of milk among people with the non-persistent genotype tended to be lower than among the lactose tolerant subjects,but was not statistically significant.CONCLUSION:An investigation of the lactase persistent genotype in a northern Russian population has not been performed before.The genotype did not affect the consumption of milk products in this population which could be explained by low consumption of milk products among the entire study population. AIM: To estimate the prevalence of the lactase non-persistent genotype (C / C-13910) in a northern Russian population in accordance with ethnicity, and to evaluate self-reported milk consumption depending on lactase activity. METHODS: Blood samples for genotyping lactase activity, defining the C / T-13910 variant by polymerase chain reaction, and direct sequencing were taken from 231 medical students of Russian origin aged 17-26 years. We analyzed milk product consumption by questionnaire which was specially designed for the estimation of milk consumption and abdominal complaints. RESULTS: We found that the prevalence of the C / C-13190 genotype in the northern Russian population was 35.6%. The other genotypes nearby C / T-13910 and associated with lactase activity were not present in the study population. The consumption of milk among people with the non-persistent genotype tended to be lower than among among the lactose tolerant subjects, but was not significant significant. CONCLUSION: An investigation of t he lactase persistent genotype in a northern Russian population has not been performed before. genotype did not affect the consumption of milk products in this population which could be explained by low consumption of milk products among the entire study population.