A Natural History Study of CMT1B, CMT2A, CMT4A and CMT4C

Charcot Marie Tooth disease (CMT) is an umbrella term that covers any inherited peripheral neuropathy. People with CMT have a problem with the nerves that go to the feet and hands that cause muscle and sensation loss, as well as difficulty with balance. There are at least forty genes that, when mutated, cause CMT. The purpose of this study is to look at the natural history of CMT to see how it changes over time. Particular emphasis will be put on studying people with CMT1B, CMT2A, CMT4A, and CMT4C, though all people with CMT are encouraged to participate. Participants are invited back on a yearly basis to determine how the changes are occurring.

Objectives:

• Determine the natural history and genotype-phenotype correlations of disease-causing mutations in CMT1B, CMT2A, CMT4A and CMT4C as well as other forms of CMT
• Determine the capability of the newly developed CMTPeds score and the Minimal Dataset to measure impairment and perform longitudinal measurements in patients with multiple forms of CMT over a ten-year window

This is a longitudinal study of individuals with CMT. Study participants will be invited to be re-evaluated every year. Evaluations will consist of neurological histories and examinations, selected nerve conduction studies (NCS) as well as completion of assorted clinical outcome measures including the CMTNS, Minimal Dataset, and Peds CMT Scale. Selected CMT patients and controls will also receive glabrous skin biopsies.

• Type: Longitudinal
• Archiver: The database of Genotypes and Phenotypes (dbGaP)