Hereditary motor-sensory neuropathies are a group of congenital diseases in which peripheral nerves are affected. These nerves consist of sensory and motor fibers: the former are responsible for transmitting pain, tactile and temperature sensations, the latter for transmitting impulses to muscles and providing movement. Since both types of nerve fibers are affected by these diseases, clinical manifestations include both sensitivity disorders (numbness, decreased pain and tactile sensitivity) and motor disorders such as muscle weakness and gradual muscle atrophy. Charcot–Marie–Tooth disease type 1A belongs to hereditary motor-sensory neuropathies and is associated with duplication of the PMP22 gene located on chromosome 17. Normally, humans have two copies of this gene, but when the corresponding part of the chromosome is doubled, there are three of them, which leads to excessive production of the PMP22 protein. This disrupts the formation of the myelin sheath of nerve fibers, causing it to thicken with the simultaneous appearance of areas of demyelination. Morphological examination of the affected nerve reveals uneven and reduced myelin content, while the exact mechanisms of demyelination are not fully understood. The disease usually manifests itself in the first two decades of life, more often at the age of 10-20 years. The initial symptom is usually weakness in the muscles of the lower extremities, accompanied by a change in gait. As it progresses, atrophy of the muscles of the legs and deformity of the feet develop, and then the muscles of the hands and forearms are involved in the pathological process. Sensory disorders are less pronounced than motor disorders. The severity and nature of clinical manifestations may vary significantly from patient to patient, including members of the same family.