β-Thalassemia Trait or β-Thalassemia Minor
People with the β-thalassemia trait (β-thalassemia minor) have only one defective HBB gene. Generally they produce enough β-globin from their fully functional HBB gene and do not show any symptoms, aside from mild anemia. They usually will not require specific treatment. However, severe anemia can develop in patients with β-thalassemia minor during pregnancy, illness or after surgery and these individuals may require blood transfusions at that point.
People that have β-thalassemia intermedia may require blood transfusions and iron chelation therapy, depending on the severity of their symptoms. Individuals with β-thalassemia intermedia are also at higher risk of developing blood clots, especially during surgery.
Ongoing treatment is required in individuals suffering from β-thalassemia major. Routine blood transfusions are necessary to maintain hemoglobin levels at 9-10g/dL. However, this treatment can also lead to further complications due to an excess of iron. Therefore, iron chelation therapy is also necessary to remove the excess iron before irreversible damage to internal organs occurs.
A splenectomy is often recommended for patients with β-thalassemia major, because it decreases the number of blood transfusions that may be required. The function of the spleen is to remove damaged red blood cells, so removal of the spleen decreases the rate at which red blood cells are eliminated. Some affected individuals, even those with only β-thalassemia intermedia or β-thalassemia minor, develop gallstones, and a cholecystectomy is recommended to remove the gallbladder.
A bone marrow transplant can be curative for some children, and involves replacing their bone marrow with the bone marrow from a healthy donor. Removal of the existing bone marrow is first required and includes chemotherapy and radiation. Bone marrow transplants are limited to severely affected patients, because of the toxicity and risks associated with the procedure.
Patients with β-thalassemia major and severe forms of β-thalassemia intermedia, should be monitored through hematological evaluations (blood tests to look at red blood cell and hemoglobin levels) every 6 to 12 months. It is also very important to monitor iron levels in these individuals, before excess iron causes severe tissue and organ damage. Children with the disease should be monitored for growth and development. Individuals with β-thalassemia may also benefit from following a diet with lower levels of iron.
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