When I had to see a gastroenterologist at one point, he was concerned about both my neuropathy and my very low ferratin levels. He said "silent celiac" can cause both symptoms, and ran a blood test. It was negative.

I did a whole exome test in December, and just got my results back a couple of weeks ago. I'm still sifting through them, but have already found one significant variant I didn't previously know about. My levels of biotinidase run half-normal levels which doesn't seem to cause much concern based on what I've read, but I will be sure to supplement for the rest of my life.

I've had this SFN for 3 1/2 years, and am not giving up. Right now I'm pursuing it from a metabolic/intestinal angle. I tore up my gastric system with iron supplements in August of 2013, and immediately developed a neuro problem. Those symptoms subsided after about a month, but two months later, the SFN set in. Even though no doctor believes there's a connection, I can't get by the coincidence.