The levels can be normal to increased in beta thalassemia. Hemoglobin F frequently increases in individuals with sickle cell anemia and sickle cell-beta thalassemia. Individuals with sickle cell and increase of Hb F have a milder case of the disease.
In cases of beta thalassemia, hemoglobin levels can be normal or elevated. Hemoglobin F is often increased in individuals with sickle cell anemia or sickle cell-beta thalassemia. Those with sickle cell and higher Hb F levels typically have a less severe condition.