Table of Contents
Definition of Thalassemia alpha/beta Disease
A genetic disorder of the blood in which the body fails to produce one or more of the proteins necessary for the synthesis of hemoglobin, the protein that enables erythrocytes (red blood cells) to carry oxygen.
The consequence is anemia (inadequate oxygen to the cells throughout the body).
There are two basic types of thalassemia: alpha and beta, designated according to the responsible defunct protein chain.
In general, thalassemia is more common among people of Asian and African heritage (alpha thalassemia) or Mediterranean heritage (beta thalassemia).
Within these types are a number of subtypes.
Symptoms and Diagnostic Path
Mild thalassemia may produce no symptoms, while severe thalassemia can be life-threatening. Symptoms are generally similar for the major forms of thalassemia and are those of anemia. They may include
- Chronic fatigue
- Shortness of breath, especially with exertion or exercise
Severe symptoms may involve cardiovascular crisis such as heart attack. Some forms of thalassemia include excessive iron absorption by the liver, heart, and other organs, resulting in permanent damage such as cirrhosis, liver failure, and heart failure.
Long-term thalassemia often results in significant splenomegaly (enlarged spleen) and permanent changes in bone structure that weaken the bones (notably with beta thalassemia). In some people the bone changes cause pathologic or spontaneous fracture, which is the first indication of an underlying thalassemia.
The diagnostic path includes blood tests to measure serum iron levels, which are characteristically elevated in severe thalassemia but may be low in mild forms, and to assess hemoglobin composition by hemoglobin electrophoresis.
Bone marrow biopsy demonstrates the altered appearance of developing erythrocytes that characterizes thalassemia. X-rays can confirm changes to the structure of the bones, which are most apparent in the skull and the long bones of the arms and legs.
Treatment Options and Outlook
People who have symptoms as a result of their thalassemia require lifelong blood transfusion, with either whole blood or packed red cells (erythrocytes), typically every two or three weeks.
These transfusions provide normal erythrocytes that can transport oxygen through the bloodstream, with transfusions timed at intervals that approximate the body’s normal process of new erythrocyte release and old erythrocyte cleansing. However, blood transfusions contribute to an escalation of iron accumulation that requires treatment, usually therapeutic chelation therapy (heavy metals detoxification).
Therapeutic splenectomy (removal of the spleen) can reduce symptoms when excessive hemolysis (acceleration of the body’s normal process for destroying erythrocytes) contributes to symptoms by stimulating increased erythropoiesis (production of new erythrocytes). Bone marrow transplantation may become a viable option when other treatment approaches fail to control symptoms and symptoms are severe.
Thalassemia is lifelong. Most people with alpha forms enjoy a good quality of life, aside from the intrusion of regular blood transfusions, and normal life expectancy. Beta forms tend to be more severe and have a less optimistic outlook. The secondary hemochromatosis (iron accumulations in the tissues) can become a significant health factor itself, creating a therapeutic dilemma.
Risk Factors and Preventive Measures
Because thalassemia is genetic and inherited, the primary risk factors are family history and presence of the causative gene mutations. Doctors advise genetic testing and genetic counseling for people who have family history of thalassemia. It is possible for an individual to carry the gene defect and show no symptoms of the condition, which can result in passing the gene defect, and the disease, to the individual’s children.