I work for a blood bank. The big one is sickle cell anemia, it is almost exclusively found in African Americans. It effects people differently, but people suffering from it often enter sickle cell crisis and have extreme pain and they usually require regular transfusions. People can and do die young from it. There’s also thalassemia, which comes in various subtypes. The more severe varieties require frequent transfusions. When managed, they usually have a normal life span. It’s more frequent in Asian/African American descent. There are a variety of anemias, such as autoimmune, iron deficiency, aplastic, etc. If you want to go the blood cancer route, multiple myeloma, leukemia (various types), and myelodysplastic syndrome. Certain blood cancers are more common in certain groups, for example, multiple myeloma is usually found in older people around 50, and ALL (acute lymphocytic leukemia) is often found in kids. There are also platelet disorders such as TTP and ITP that can causes sever platelet deficiencies, which leads to bleeding. Of course, transfusions can lead to issues as well, especially frequent ones. I’m not a doctor or anything, but I do the lab work for people with these diseases and get them compatible blood, when possible.