Beta globin is made by two genes (HBB), one on each chromosome 11. Mutations in the HBB gene prevent the production of beta hemoglobin, leading to a diminished amount of hemoglobin, which results in red blood cells not developing normally. b –Thalassemia results from this type of gene mutation, which could happen in one or both of the beta globin genes. The severity of the anemia caused by b-Thalassemia depends on which mutations are present and on whether they decrease beta globin production or completely eliminate it. The different types of b-thalassemia include: · Beta Thalassemia trait (one of the two genes is abnormal): a person with this condition simply carries the genetic trait for beta thalassemia and will usually experience no health problems other than mild anemia. This gene mutation could be passed on to an individual’s children. · Thalassemia Intermedia (two abnormal genes but is still producing some beta globin): causes a moderately severe anemia and significant health problems including bone deformities and enlargement of the spleen. Patients may need occasional transfusions but do not require them on a regular basis. · Thalassemia Major (also called Cooley’s Anemia – two abnormal genes with the lack of beta globin production): causes a life-threatening anemia that requires regular blood transfusions and extensive ongoing medical care. Patients are jaundiced, leg ulcers and cholelithiasis occur, and splenomegaly is common.