OBJECTIVE Ref fling pathogenesis factors and the role of disorders of gastric secretion in the formation of the syndrome of malnutrition in patients with connective tissue dysplasia patients. METHODS In a cross-sectional comparative cohort study 83 patients were included: 59 patients with signs of connective tissue dysplasia (study group) and 24 patients with no signs of connective tissue-dysplasia (control group). In all patients the gastrointestinal symptoms were evaluated using a questionnaire GSRS, esophagogastroduodenoscopy, 24-hours pH monitoring, diagnostics H.pylori infection. RESULTS in patients with connective tissue dysplasia the higher scores were recorded at body pH 1.2 (1.0; 2.8) and antral stomach 8.9 (6.6; 10.0). According to the morphological study the mucosal damage prevalents as pangastritis (20%), fundic gastritis (4%). Changes of intranagastric pH were associated with high rates of duodeno-gastric reflux in 74.5% patients. The severity of symptoms of dyspepsia (postprandial distress syndrome) and the degree of malnutrition correlated with indicators of intragastric pH in the body and antrum. CONCLUSIONS The changes revealed intragastric pH may signifcantly alter the digestive conditions in all parts digestive tract contributing desynchronization receipt chyme and enzymes disrupting the normal regulation of pancreatic secretion, promoting the development of maldigestion syndromes, malabsorprion and, consequently aggravate genetically determined disorders trophological status.