The aim of the study was to examine an association of the rs602662 FUT2 genetic locus with the status of H. pylori infection and development of related diseases (chronic gastritis, gastric ulcer and 12 duodenal ulcer).Methods: The study included 91 patients, divided into two groups - "case" and "control". Criteria for the “case” group enrollment: diagnosis of gastric or duodenal ulcer, chronic non-atrophic gastritis; positive test for H. pylori.The “control” group included patients with episodic complaints of dyspepsia while undergoing a comprehensive examination, with negative test for H. pylori, as well as having no history of former therapy on H. pylori elimination.The study for the presence of the polymorphic locus rs602662 of the FUT2 gene was carried out by the standard TaqMan PCR method on a Real-Time CFX96 Touch amplifier. The follow-up period was 6 months.Results: The main group included 50 patients aged 21 to 50 years, the control group – 41 patients. Patients infected with H. pylori more often noticed symptoms of dyspepsia - in 36%, compared with the control group - 9.7%. A family history of associated diseases in the main group was significantly differed, χ2 = 4.97, p 0.05.To assess the contribution of the rs602662 locus genotype in FUT2 gene to the risk of clinically manifested H. pylori infection, the main group was divided into subgroups. In the distribution of alleles in these groups, significant differences were revealed. Allele "A" has a protective effect regarding the onset of clinical symptoms of dyspepsia. The odds ratio (OR) with the carriage of allele "A" (genotypes A / A and G / A versus G / G) to have clinical symptoms with a positive H. pylori status was 0.175 (CI = [0.049-0.625] chi2 = 7.79 p = 0.0053 ).Conclusion:1. No association of alleles and genotypes of the rs602662 locus of the FUT2 gene with the status of H. pylori infection was revealed.2. Carriage of allele "A" have a significant association with the absence of clinical symptoms in patients with a positive status of H. pylori infection, OR 0.175 (CI = [0.049-0.625] chi2 = 7.79 p = 0.0053).