Welcome to NeuroTalk:

Please visit our subforum here on neuropathy:

http://neurotalk.psychcentral.com/forum119.html

Lots of information on testing, causes, healing supplements, CMT testing.

The regular forum is mostly for asking questions, and conversation:
http://neurotalk.psychcentral.com/forum20.html

There are many triggers for PN... common drugs, toxins, and even that vaccine you got because it was advertised on TV or elsewhere.

The CMT thread on the subforum explains hereditary types, and gives links for you to study.

You need to check nutrient levels for B12 and Vit D and get the numerical result instead of "normal" comments from your doctor. Doctors will test but they don't often interpret the results accurately.
B12 and Vit D are the most commonly low in many people.

Also magnesium may help. This can cut down on twitching/cramping and other sensations. A good oral form (not Oxide, which is not absorbed) or topical lotion type like Epsom-IT, or Kirkman magnesium cream, can often help quite a bit. Up to 70% of Americans are low in magnesium and blood testing is too crude to show it except for extreme values.

What your doctor can do for you testing wise is limited, as well as treatments. So do visit the links I gave and expect to read some...it is 6+yrs of accumulated knowledge and experience.