As I am about to donate stem cells for a person with a disease of the hematopoietic system, I am currently very interested in the topic and would like to understand more, but I am not completely familiar with the subject. When selecting a donor, attention is paid to various HLA characteristics in order to have a 10/10 match in the best case scenario.
Is it a coincidence that unrelated donors and recipients have the same HLA characteristics?
And the second question is probably clarified by the answer to the first question and the fact that even siblings only have a 25% chance of being suitable donors: is there a possibility of a distant relationship if some (or all?) HLA characteristics match?
Perhaps someone has an explanation for me, in detail if possible, or any websites, papers or anything else that explains this in more detail.
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Why do some mountains have soil on top, while others are made of rocks? Does the elevation have do with it? It seems than the taller the mountain, the more likely that its peak is made of rocks?