The article presents the main characteristics of the Syndrome of undiff erentiated connective tissue dysplasia, refl ecting the essence of this problem in the system of public health, in particular children and adolescents. The mechanism of the formation of this condition and its clinical manifestations are consecrated.

Due to the spread of undiff erentiated forms of connective tissue dysplasia, it seems relevant to assess the impact of organogenesis disorders on the physical development of schoolchildren living in the northern region. What dictates the need to study the interrelationships and interdependencies of the components of physical development and somatometric indicators in children of the north with phenotypic markers of UCTD. The eff ect of posture disorders on the studied components of physical development is manifested by higher growth in children with a fl at and round-concave back, a decrease in the thickness of skin-fat folds and the size of the head with a round and round-concave back. Therefore, to analyze the intersex and age diff erences in physical development in children with NDT, it is necessary to take into account the dynamics of interdependent anthropometric indicators and indices, taking into account the types of posture disorders.

The article analyzes the data of an anthropometric and somatotypological study of 164 boys and 93 girls of the northern region, different sexual somatotypes with different severity of signs-phenes of undifferentiated connective tissue dysplasia. It was found that 44% of boys and 22% of girls with d, according to sexual somatic differentiation, correspond to the biological sex, 34% of boys and 53% of girls have mild gender dysplasia in the form of mesomorphy, and 19% of boys and 21% of girls have signs of sex inversion. Undifferentiated connective tissue dysplasia affects the severity of morphotypological differences between sexual somatotypes and the appearance of signs of gracialization within them. Key words: northern region, adolescence, sexual dimorphism, undifferentiated connective tissue dysplasia.