I have not posted for a while, donated to a person the hospital matched me with, 2005; became sick in about 2007, progressive, neurological, later found to be Lyme, but with a twist, I became sicker from most medications. Was tested for MTHFR gene mutation, I had both, 667 and 12XX (cannot remember exact number). These mutations, which affect various issues, but in my case, problems with methalation, the removal of toxins (and medications, etc). When you add low kidney function to this, I have a very hard time being treated for Lyme, surgery and so on. So I have a little advise for people thinking about being a donor, pay (or get the transplant center) to pay the $200 to be tested, if positive for one (or esp. both) learn about the mutation issues before deciding to be a donor. If you are a donor who is having problems ask your doctor to do this simple, cheap test; as the impact of having the mutation(s) can be offset to a degree. The mutations were "discovered" in about 1995, by the genome project; there has been a lot of research about them sense. The prevalence is about 10% worldwide. Best wishes, Rob