Disability Severity Scale (DSI) and Hereditary Motor and Sensory Neuropathy Overall Disability Scale (HMSN-R-ODS)

Charcot Marie Tooth Disease (CMT) is a group of disorders that cause a peripheral neuropathy, impairing the long nerves that go to the feet and hands. Due to the problems with the peripheral nerves, people with CMT have muscle weakness and sensory loss that impairs their physical abilities. CMT affects approximately 1 in 2500 people and is caused my mutations in over 70 different genes. Models exist for many sub-types of CMT that have led to an increased understanding of the biological basis for these disorders. These advances have also made rational therapies for CMT a realistic possibility. However, clinical trials have been limited in CMT by a combination of lack of natural history data for many subtypes, a lack of outcome measures that can detect change in a short period for slowly progressive forms of CMT, and a lack of outcome measures for young children with CMT. In order to develop treatments based on the biological advances in the inherited neuropathies, it is necessary to have measured the natural history of the various disorders. It is only by knowing the natural history that one understands the onset of clinical symptoms, the rate of progression, and the ultimate prognosis of these diseases. For these reasons, the INC has dedicated much of its effort to develop sensitive outcome instruments, including PRO tools, to measure the natural history of CMT. It is the investigators goal to establish such an instrument for overall impairment for use in both natural history analysis and clinical trials. To develop and validate this instrument, the investigators will be asking people who have CMT to complete two questionnaires, the DSI and the HMSN-R-ODS. These relate to overall symptom impairment due to CMT. These instruments may be used to help us understand the overall progression of CMT and will ultimately help with clinical trials when they are available for the various forms of CMT.