(Also: we didn't really know much about #PNH - paroxysmal nocturnal haemoglobinuria - nor how it related to our son's #AplasticAnemia. But it's a disease, that often coincides with #AplasticAnemia, which causes the membrane of red blood cells to fail, and then the heamoglobin"falls out" into the blood stream - called #haemolysis. This website was really useful: https://my-pnh.com/pnh-resources )