There is DNA testing for CMT. It is very expensive. There are many many types of CMT. The most common type is CMT 1A. It has a duplication where HNPP has a deletion.

Scroll down to the PN site. There is a spot to click on for PN Tips, Resources, Supplements and Other Treatments. If you go down a ways you will find my posts concerning CMT and HNPP.

The fact that your feet are different does not mean that you do not have CMT. CMT feet can look normal, flat footed, high arches, or one high and one low.

You say you mention Frederick's Ataxia is interesting. That's one disease that CMT is often misdiagnosed as. From what you say about your brother it certainly can be in your family. You can be young, old, or in-between before any symptoms might occur. Or they may never be evident at all but you still can have CMT.

CMT symptoms vary greatly even within the same family. I hope you find the answer.