07 Apr Thalassemia
Thalassemia is a group of inherited (passed from parents to children) blood disorders that can cause mild to severe anemia (lack of blood). To understand how thalassemia affects the human body, one must understand how red blood cell is made.
Hemoglobin is the protein in red blood cells that carries oxygen to all parts of the body. It consists of two different proteins, an alpha and a 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 sufficient oxygen. This results in anemia that begins in early childhood and lasts throughout life.
There are two main types of thalassemia, alpha and beta thalassemia. Alpha thalassemia occurs when there is a problem with the alpha globin chain that is part of hemoglobin. Beta thalassemia occurs when there is a problem with the beta globin chain. The genes for each type of thalassemia are passed from parents to their children.
It is commonly found in Southeast Asian, Indian, Chinese, or Filipino origin or ancestry. There are 3 subtypes of alpha thalassemia that range from mild to severe in their effect on the body.
- Minor (trait): This generally causes no health problems because the lack of alpha protein is so small that the hemoglobin functions normally.
- Intermediate: In this condition, the lack of alpha protein is somewhat greater. Patients with this condition have smaller red blood cells and a mild anemia, although many patients do not experience symptoms. Mild complications can develop and require medical treatment.
- Alpha Thalassemia Major. Alpha thalassemia major can result in miscarriages. Usually the baby dies in the second or third trimester of pregnancy or shortly after birth. In some extremely rare cases blood transfusions of the baby inside the womb have allowed the birth of children who then require lifelong blood transfusions and medical care.
It is found in people of Mediterranean descent, such as Italians and Greeks, and is also found in Southeast Asia and southern China. Like alpha thalassemia, there are three types of beta thalassemia that also range from mild to severe in their effect on the body.
- Minor (trait): In this condition, the lack of beta protein is not great enough to cause medical problems other than a possible mild anemia.
- Intermediate. In this condition the lack of beta protein in the hemoglobin is great enough to cause a moderately severe anemia and significant health problems, including bone deformities and enlargement of the spleen.
- 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 and extensive blood transfusions. These extensive, lifelong blood transfusions lead to deposit of iron (iron overload) in various organs which must be treated with chelation therapy to prevent early death from organ failure.
If two people with same thalassemia trait (alpha or beta) have a baby, the following possibilities can happen:
- The baby could receive two normal genes (one from each parent) and will be born normal (1 in 4 chances).
- The baby could receive one normal gene from one parent, and abnormal gene from the other parent, and have thalassemia trait (2 in 4 chances).
- The baby could receive two thalassemia genes (one from each parent) and have a moderate to severe form of the disease (1 in 4 chances).
Symptoms of severe thalassemia in early childhood include:
- Fatigue (feeling tired) and weakness
- Pale skin or jaundice (yellowing of the skin)
- Protruding abdomen with enlarged spleen and liver
- Dark urine
- Abnormal facial bones and poor growth.
Thalassemia is diagnosed using blood tests, including a complete blood count (CBC) and special hemoglobin studies. Prenatal testing using chorionic villus sampling or fetal blood sampling (taking blood from baby’s umbilical cord) can determine if an unborn baby has thalassemia and how severe it is likely to be. However, both tests are invasive and carry risks of miscarriage or stillborn.
Treatment for thalassemia depends on the type and severity of the disease.
- People who are carriers (thalassemia trait) usually have no symptoms and need only folic acid supplements. Folic acid is a B vitamin that helps build red blood cells.
- Those with moderate or severe thalassemia have a serious and life-threatening illness. They are treated with:
- Regular blood transfusions,
- Iron chelation therapy: medicine is used to remove the excess iron that builds up in the body when a person has regular blood transfusions. If the iron is not removed, it damages body organs such as the heart and liver.
- Bone Marrow or Stem Cell Transplants: This is a risky procedure, but it offers a cure.
Without treatment, children with severe thalassemia do not live beyond early childhood.