I wrote this post because my mother almost passed away at 54 years old from chemo toxicity as a result of an undiagnosed DPD deficiency. Basically,  the DPD enzyme is responsible for breaking down uracil and thymine and is also needed to break down chemotherapy (specifically FLUOROURACIL (5FU) or CAPECITABINE) in your body. When you normally take chemotherapy, the chemo is meant to destroy the cancerous cells. You are able to survive chemotherapy normal because your body should normally be able, to metabolize and excel it from the body.  If you have a DPD deficiency and take these chemotherapies, your body isn't able to metabolize the chemo and you are left with life threatening levels of the chemo in your body with no way out. Essentially, the chemo poisons you and the more doses you take the worse the reaction you have. My mother was at one of the best cancer hospitals in the world, attended to by leading physicians, and had a strong support system in her family which oversaw her care. Despite all these benefits, she still almost died because of this DPD deficiency. If it could happen to my mom despite all the advocates she had, I can only imagine what goes on for those facing cancer alone or at hospitals of lesser caliber. I hope that by telling her story in this post I can help others prevent this from happening or help to best treat and recover from chemo toxicity if they are already at that point.