Charcot-Marie-Tooth disease (CMT) is a group of progressive disorders that affect the peripheral nerves and result in problems with movement and sensation. In CMT type 2 (CMT2), the motor system is more prominently involved than the sensory system, although both are involved. Individuals with this condition typically have slowly progressive weakness and atrophy of distal muscles in the feet and/or hands usually associated with depressed tendon reflexes and mild or no sensory loss. There is significant clinical overlap with CMT1. The subtypes of CMT2 are similar clinically and distinguished only by molecular genetic findings.
Charcot-Marie-Tooth disease type 2C (CMT2C) is a very rare form of CMT. Individuals with this condition may have diaphragm or vocal cord paresis in addition to the other problems associated with CMT. Mild sensory loss has also been noted in some individuals. CMT type 2C is caused by mutations in the TRPV4 gene on chromosome 12q24. Source: Genetic and Rare Diseases Information Center (GARD), supported by ORDR-NCATS and NHGRI.