hi, i have heriditary pn determined by my sural nerve biopsy and all other tests negative as far as cause.... the nerve biopsy shows severe damage - before they did the sural nerve though they did all the dna testing available (plus all your standard tests that showed no nerve conduction, etc) but auto-immune, spinal, sjogrens etc all ok... my doc treated me with high dose weekly ivig saying i had cidp based on i dont know what - but it did not help - now they are sure its a form of heridiatary there is no genetic test yet for HSANII....

i dont know how the skin biopsy feels or if it shows as much as the sural nerve, but my recovery from the sural nerve was only a day or so, even with 12 stiches in my leg.... it is numb 10 years later, but was before, so no biggie... they used some kind of anesthsia that didnt work when they cut the nerve itself, yes, that hurt like heck, but the doc said that shouldnt have happened.... and was over in a second.....

hope you can get some resolve - at least then they can give prognosis and you know what you are dealing with!