Visceral disorders of various organs and systems in children with connective tissue dysplasia (CTD) living in extreme climatogeographic conditions according to laboratory tests have been studied. The children (35 schoolchildren) aged 10 to 17 years old were divided into mild, moderate and pronounced CTD degrees. Selection of children was performed by CTD phenotypic signs with score assessment and definition of CTD severity. The results of laboratory studies revealed more than 90 % cardiovascular system disorders in children with CTD, about 85 % of digestive system disorders and 70 % of visual disorders, 50 % of urinary disorders were detected in half of the children, mineral metabolism was impaired in 44 % of the children. The connective tissue dysplasia in 70 % of the children causes changes of 2 or more systems and organs, and in half (55 %) causes 3 or more systems and organs disorders. When examining children with EchoCG, almost the majority of Cardiovascular Development Abnormalities (CDA) were detected. In more than half of children, 65.8 %, i.e., 25 children were diagnosed with mitral valve prolapse (MVP). Mitral valve regurgitation was found in 28 children (73.8 %), MVP of the 1st degree was noted in half of children with CTD, and the second degree was noted in 16 % of the children and adolescents. In ten children (26 %), abnormally located chords (ALC) were diagnosed, 13 children (34 %) showed additional trabecules. The compaction of the calices-pelvis system walls occupies a special place in children with CTD.