Aggressively returned (polyneuropathy) numbness/stiffness has advanced from feet to upper legs and hands in a couple of weeks, showing no signs of stopping. Been on methyl B-12 for six months enjoying remission but unexplained quick return of symptoms is not responding to trials of mix of MB-12, methylfolate, and potassium. Looks so much like a methylation block. I believe a Methylation Pathway panel is called for. Which labs provide best quality with relatively quick turnaround?