 The first large scale survey to identify items that best reflect the issues and symptoms with high impact upon QOL in CMT will be sent out in a second wave. This second wave will only contain the QOL survey and not the muscle cramp survey. The QOL survey will be distributed via an online link to three populations: adult CMT patients self-registered with the INC RDCRN Contact Registry who had not been registered at the time of the first enrollment period, adult patients who had been registered at the time of the first enrollment period and had received the survey, but had not returned it, and patients who were registered, but were under age 18 at the time of the first enrollment period and have turned 18 by the time of the second enrollment period. 