Some of the rare blood disorders include Aase Syndrome, Megaloblastic Anemia, POEMS syndrome, Blackfan Diamond and Congenital Heart Block. Eosinophilia is another type of blood disorder where a patient has an abnormally high number of eosinophils in their blood. You can check out http://www.bloodbook.com/blood-rarediso.html for some of the listed blood disorders.
I had ITP blood disease (idiopathic thrombocytopenic purpura) when I was about 8 years old. It is when your body is low on platelets. You are supposed to have about 8000 platelets in your body. I only had 2 left. I almost died in the hospital. I was covered in purplish tiny spots all over my body. Even on my eyes and in my mouth. Everywhere. I still remember the taste of blood. And the scary huge purple bruise where my heart was which frightened my mom who stayed there with me in the hospital everyday and night till i was aloud home again. And if you get hurt, or accidentally slightly hurt yourself while you have this disease you die. I am happy I'm fine now. I did developed a bit of post-traumatic stress disorder after this though.