This project is to develop a new CMT Pediatric Scale (CMTPeds) for Children with CMT. Although there is a validated score (the CMTNS) which measures disease severity for CMT, it is not always applicable to children due to their limited ability to relay information about their symptoms. The CMTPeds scale is being developed and validated in order to measure disease severity in children and have outcome measures available for future clinical trials. Children (defined as 21 and under) being evaluated will be asked to perform functional tasks such as using stairs, walking in a hallway, and performing hand function tests. This information will be used to validate the CMTPeds score. It is important to have validated instruments to measure disease severity in childhood so these can be used with clinical treatment trials are available.
Inclusion Criteria: All patients MUST be seen in person at one of the participating centers for enrollment in this study. - Children (< 21 years of age) - Known or probable inherited neuropathies classified as CMT1, CMT2, or CMT4 Exclusion Criteria: - Known diagnoses of acquired neuropathy including toxic (e. g. medication related neuropathies); metabolic (e.g. diabetic), immune mediated or inflammatory [acute inflammatory demyelinating polyradiculoneuropathy (AIDP) or chronic inflammatory demyelinating polyneuropathy (CIDP)] polyneuropathies; neuropathy related to leukodystrophy, congenital muscular dystrophy; and patients with severe general medical conditions. - Entirely normal conduction velocities of upper and lower limbs as this suggests that the subject may not have a neuropathy.