Marquita Williams is a year - old medical student with stem cell disease . Broad cell disease is a genetic blood disorder that can cause severe pain . Gaines receives a red blood cell exchange transfusion every two weeks . Each exchange transfusion contains 10 units of red blood cells .
Marquita Gaines is a 20-year-old college student with sickle cell disease . Sickle cell disease is a genetic blood disorder that can cause severe pain . Gaines receives a red blood cell exchange transfusion every six weeks . Each exchange transfusion requires 10 units of red blood cells .