Thalassemia and other Hemoglobinopathies

Thalassemia is the name of a group of inherited blood disorders. It is characterized by less hemoglobin and fewer red blood cells in your body than normal. Hemoglobin is the part of the red blood cells that carry oxygen. It consists of two different proteins, alpha and beta. If the body doesn't produce enough of either of these two proteins, the red blood cells do not form properly and cannot carry enough oxygen. That becomes anemia and lasts throughout life.

Thalassemia is not a single disorder but a group of related disorders that affect the human body in similar ways. We typically see the following: Alpha Thalassemia, Beta Thalassemia and Hemoglobin E. Alpha Thalassemia People whose hemoglobin does not produce enough alpha protein have alpha thalassemia. It is commonly found in Africa, the Middle East, India, Southeast Asia, southern China, and occasionally the Mediterranean region. Alpha globin is made by four genes. If an individual has one or two abnormal alpha globin genes, they will have alpha thalassemia trait. Silent Carrier State. This condition is very mild and generally there are no health problems because the lack of alpha protein is so small that the hemoglobin functions normally. It is difficult to detect and thus called "silent carrier". Silent carriers are "diagnosed" when an apparently normal individual has a child with hemoglobin H disease or alpha thalassemia trait.

Alpha Thalassemia Trait or Mild Alpha Thalassemia. The lack of alpha protein is greater with this disease than the Silent Carrier State. These patients have smaller red blood cells and a mild anemia, although many do not experience symptoms of any kind. Many physicians often mistake mild alpha thalassemia for iron deficiency anemia and prescribe iron supplements that do not help this condition.

Hemoglobin H Disease. Because the lack of alpha protein is great enough to cause severe anemia and serious health problems such as an enlarged spleen, bone deformities and fatigue, this is a more severe form of Alpha Thalassemia. Hydrops Fetalis or Alpha Thalassemia Major. With this condition, there are no alpha genes in the child's DNA, which causes the gamma globins produced by the fetus to form an abnormal hemoglobin called hemoglobin Barts. Many individuals diagnosed with this condition die before or shortly after birth. In extremely rare cases where the condition is discovered before birth, in utero blood transfusions have allowed the birth of children but they then require lifelong blood transfusions and medical care.

Beta Thalassemia. People whose hemoglobin does not produce enough beta protein have beta thalassemia. It is found in people of Mediterranean descent, such as Italians and Greeks, and is also found in the Arabian Peninsula, Iran, Africa, Southeast Asia and southern China. There are three types of beta thalassemia that also range from mild to severe in their effect on the body.

Thalassemia Minor or Thalassemia Trait. A person with this condition simply carries a genetic trait for thalassemia and will usually have no health problems other than possibly mild anemia. As in mild alpha thalassemia, this is often mistaken in the small red blood cells of the person with beta thalassemia minor as iron-deficiency anemia and incorrectly prescribed iron supplements.

Thalassemia Intermedia. The lack of beta protein in the hemoglobin is great enough, in this condition, to cause moderately severe anemia and significant health problems, including bone deformities and enlargement of the spleen. There is a wide range in the clinical severity of this condition. The determining factor is the amount of blood transfusions required by the patient - the more dependent the patient is on blood transfusions, the more likely he or she is to be classified as thalassemia major. Patients with thalassemia intermedia need blood transfusions to improve their quality of life, but not in order to survive.

Thalassemia Major or Cooley's Anemia. This is the most severe form of beta thalassemia in which the complete lack of beta protein in the hemoglobin causes a life-threatening anemia that requires regular blood transfusions and extensive ongoing medical care. These extensive, lifelong blood transfusions lead to iron-overload which must be treated with chelation therapy to prevent early death from organ failure.

Hemoglobin E E Beta Thalassemia. Hemoglobin E is a common but minor blood abnormality. It is usually found in people of Southeast Asian, such as Cambodians, Vietnamese and Thailand. They are usually quite healthy and have few symptoms related to their blood disease. It is often identified because there are abnormalities in the size and appearance of red blood cells when looked at under the microscope. There could be a hemoglobin electrophoresis that is also abnormal in hemoglobin E. You can live a normal, healthy life with Hemoglobin E but since it is a genetic trait, it is important to know so that you can determine, as you decide to have children, the chances of passing along a serious blood disorder.