AIM: To estimate the prevalence of the lactasenon-persistent genotype (C/C-13910) in a northRussian population in accordance with ethnicity, and toevaluate self-reported milk consumption depending onlactase activity. METHODS: Blood samples for genotyping lactaseactivity, defining the C/T-13910 variant by polymerasechain reaction, and direct sequencing were taken from231 medical students of Russian origin aged 17-26 years.We analyzed milk product consumption by questionnairewhich was specially designed for the estimation of milkconsumption and abdominal complaints. RESULTS: We found that the prevalence of theC/C-13190 genotype in the north Russian populationwas 35.6%. The other genotypes nearby C/T-13910and associated with lactase activity were not present inthe study population. The consumption of milk amongpeople with the non-persistent genotype tended to belower than among the lactose tolerant subjects, but wasnot statistically significant. CONCLUSION: An investigation of the lactase persistentgenotype in a north Russian population has notbeen performed before. The genotype did not affect theconsumption of milk products in this population whichcould be explained by low consumption of milk productsamong the entire study population.