Abstract
Hereditary neuropathy is a clinically and genetically heterogeneous group of diseases which most often represent a hereditary neuromuscular disorder. The prevalence is approximately 17-40 per 100,000.
The most frequent form is called Charcot-Marie-Tooth disease (CMT) or hereditary motor and sensitive neuropathy (HMSN). In most cases, the clinical symptoms appear in the 1st and 2nd decade and include atrophy and weakness of lower limb muscles (peroneal atrophy), the pes cavus deformity of the foot with a shortened Achilles tendon, areflexia in the lower limbs and the stocking type sensory disorder.
The basic classification of hereditary neuropathies is based on electrophysiological studies which classify CMT disease into two basic types. Type no. 1 - demyelinisation - with the n. medianus motor fibre conduction velocity at forearm below 38 m/s, and type no. 2 - axonal - with a velocity above 38 m/s.
Molecular geneticists have so far identified causal mutations in 40 genes and have made a major contribution to molecular genetic classification of CMT disease and to the understanding of pathogenesis of the most frequent forms of hereditary neuropathies. Heredity involves all types of monogenic Mendelian inheritance: autosomal dominant, autosomal recessive and gonosomal dominant.
Because causal therapy does not exist, current therapeutic approach is based on rehabilitation, prosthetic and orthopedic treatment. In a vast majority of cases, the prognosis of patients is good as this condition does not impair their standard life expectancy, even though it has a major impact on the patients' quality of life.