Alpha Thalassemia

Definition

Definition of Alpha Thalassemia
Alpha-thalassemia (a-thalassemia) is a form of thalassemia involving the genes HBA1 and HBA2. Alpha-thalassemia is due to impaired production of 1,2,3, or 4 alpha globin chains, leading to a relative excess of beta globin chains. The degree of impairment is based on which clinical phenotype is present (how many chains are affected).

Symptoms

Symptoms of Alpha Thalassemia
Hb Bart syndrome is characterized by hydrops fetalis, a condition in which excess fluid builds up in the body before birth. Additional signs and symptoms can include severe anemia, an enlarged liver and spleen (hepatosplenomegaly), heart defects, and abnormalities of the urinary system or genitalia.

Causes

Causes of Alpha Thalassemia

1. It is most commonly inherited in a Mendelian recessive fashion. It is also connected to the deletion of the 16p chromosome.
2. It can also be acquired, under rare circumstances. Due to the low occurrence of alpha-thalassemia, the disease can be mistaken for iron deficiency anemia.

Diagnosis

Diagnosis of Alpha Thalassemia
Alpha thalassemia is most commonly found in Africa, the Middle East, India, Southeast Asia, Southern China, and the Mediterranean region. Carrier status can be determined by the following:

1. Complete blood count (CBC) - a measurement of size, number, and maturity of different blood cells in a specific volume of blood.
2. Hemoglobin electrophoresis with A2 and F quantitation - a lab procedure that differentiates the types of hemoglobin present.
3. FEP (free-erythrocyte protoporphyrin) and ferritin - to exclude iron deficiency anemia.

Treatment

Treatment of Alpha Thalassemia

1. Avoid iron supplementation as it contributes to iron overload and does not affect hematologic values or cell morphology.
2. Administer folate supplementation to provide adequate amounts of the vitamin for increased utilization resulting from the hemolytic process and high bone marrow turnover rate.
3. Provide prompt attention to infection, especially in children who have had splenectomy, and administer appropriate vaccines to these individuals.
4. Administer blood transfusions only if necessary.
5. If chronic transfusion is needed (hemoglobin H disease), iron chelation therapy should be considered to avoid iron overloading.

Prognosis

Prognosis of Alpha Thalassemia
Patient outlook is dependent on the type of alpha-thalassemia present. Those with alpha-thalassemia silent carrier or alpha-thalassemia trait are usually asymptomatic and require only education and appropriate genetic counseling. Those with Hb H disease have a phenotype of variable severity, although they generally lead normal lives. Patients must be educated about complications (exacerbations of hemolysis, cholelithiasis, ulcers, and growth retardation) and should be monitored as they grow older for the development of iron overload. Pregnant patients with Hb H disease should be followed carefully for the development of severe anemia and other complications.

Prevention

Prevention of Alpha Thalassemia
Consult with your doctor.