Hereditary neuropathies are a heterogeneous group of disorders.
Charcot-Marie-Tooth disease (CMT) or sensory-motor neuropathy is the most common hereditary neuromuscular disease, with a prevalence of 1/2,500 individuals (Suter and Sherer, 2003).
CMT is a complex disorder at the molecular level, with at least 1,000 genetic variants associated with approximately 80 genes (Timmerman et al., 2014). In the large series described, the molecular alteration is identified in 60-70% of patients (80% of demyelinating forms and 25% of axonal forms) (Rossor et al., 2015). Around 90% of the alterations are distributed in the PMP22, MPZ, GJB1 and MFN2 genes (DiVicenzo et al., 2015), although this figure varies between populations, being particularly reduced in regions with a high prevalence of forms with recessive inheritance. 40-50% of CMT cases are demyelinating or type 1 (CMT1), of which 70-80% are caused by the duplication of a region of approximately 1.5 Mb containing thePMP22 gene. (CMT1A).
Hereditary motor neuropathy (HMN) comprises 10% of all hereditary neuropathies, with a diagnosis rate of 20-32% (Bansagi et al., 2017).