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.

Inclusion Criteria:

- individual has an inherited peripheral neuropathy or is suspected to have an inherited
peripheral neuropathy

- individual is 10-99 years of age

- individual signs consent or assent form depending on age and requirements

- individual is participating in INC 6601 at one of the participating sites OR is a
participant on the INC Patient Registry

Exclusion Criteria:

- inability to provide informed consent

- outside of age range

- inability to complete questionnaire

- does not understand English

- is not participating in INC 6601 or on the INC Patient Registry