I get a lot of great friends and family asking if they can be the ones to donate bone marrow to Clark for his transplant. It’s a great question, and we really appreciate the offers, but unfortunately most will not be a match.
About 70% of patients who need a transplant do not have a suitable donor in their family. Half of Clark’s HLA genetic markers are inherited from myself (his mother) and from Patrick (his father). Each sibling has only a 25% chance of matching. We already know that Connor is not a match (unfortunately). Likewise, it is highly unlikely that other family members will match Clark. Under very rare circumstances, family members other than siblings may be tested. Case in point might be where 2 sisters married 2 brothers. Cousins from the other couple might be a great match. No such luck in our case.
Human leukocyte antigen (HLA) typing is used to match Clark with a donor for bone marrow. This is not the same as ABO blood typing. HLA is a protein – or marker – found on most cells in your body. Your immune system uses HLA markers to know which cells belong in your body and which do not. It is “acceptance” that is being sought after here. If the body rejects the transplant, it can be a catastrophe.
There are 12-13 genetic markers that are tested to define a bone marrow “match”. The odds that two random individuals are HLA matched exceeds one in 20,000. This is why it is so important for eligible donors to register.
The factors for Clark are largely Irish and German (with some Welch, Norwegian and other European Countries). So if you are full Irish, or half Japanese, then you most definitely won’t match. But if your grandfather was Irish, and your grandmother was German, there might be a match there. We are basically looking for people that might have been from the same “village” (back in the days those existed).
However, even if you are of a different nationality than Clark, please consider donating “in kind” for Clark. Donating actually isn’t a huge procedure, and you very easily could save someones life.