Thalassemia is the name of a group of genetic blood disorders. To understand how thalassemia affects the human body, you must first understand a little about how blood is made.
Hemoglobin is the oxygen-carrying component of the red blood cells. 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. The result is anemia that begins in early childhood and lasts throughout life.
Hemoglobin is made of 2 proteins:
Thalassemia occurs when there is a defect in a gene that helps control production of 1 of these proteins.
There are 2 main types of thalassemia:
Alpha thalassemia occurs when a gene or genes related to the alpha globin protein are missing or changed (mutated).
Beta thalassemia occurs when similar gene defects affect production of the beta globin protein.
There are many forms of thalassemia. Each type has many different subtypes. Both alpha and beta thalassemia include the following 2 forms:
You must inherit the gene defect from both parents to develop thalassemia major
Thalassemia major is the most severe form of anemia, and the oxygen depletion in the body becomes apparent within the first 6 months of life. If left untreated, death usually results within a few years. Note the small, pale (hypochromic), abnormally-shaped red blood cells associated with thalassemia major. The darker cells likely represent normal RBCs from a blood transfusion.
Thalassemia minor occurs if you receive the faulty gene from only 1 parent. People with this form of the disorder are carriers of the disease. Most of the time, they do not have symptoms.
This blood smear from an individual with thalassemia shows small (microcytic), pale (hypochromic), variously-shaped (poikilocytosis) red blood cells. These small red blood cells (RBCs) are able to carry less oxygen than normal RBCs.
The most severe form of alpha thalassemia major causes stillbirth (death of the unborn baby during birth or the late stages of pregnancy).
Children born with beta thalassemia major (Cooley anemia) are normal at birth, but develop severe anemia during the first year of life.
Other symptoms can include:
Bone deformities in the face
Shortness of breath
Yellow skin (jaundice)
People with the minor form of alpha and beta thalassemia have small red blood cells but no symptoms.
Severe thalassemia can cause early death (between ages 20 and 30) due to heart failure. Getting regular blood transfusions and therapy to remove iron from the body helps improve the outcome.
Less severe forms of thalassemia often do not shorten lifespan.
Treatment for thalassemia major often involves regular blood transfusions and folate supplements.
A bone marrow transplant may help treat the disease in some people, especially children.
But both this treatments are costly and not everyone can afford it. Also it doesn't guarantee the sure cure since body is receiving elements which are imported and not self body generated. It sometimes results in other chronic medical problems which the patient sometimes have to carry all his life.
How Can Thalassemias Be Prevented?
You can’t prevent thalassemias because they’re inherited (passed from parents to children through genes). However, prenatal tests can detect these blood disorders before birth.
Family genetic studies may help find out whether people have missing or altered hemoglobin genes that cause thalassemias. (For more information, go to "How Are Thalassemias Diagnosed?")
If you know of family members who have thalassemias and you're thinking of having children, consider talking with your doctor and a genetic counselor. They can help determine your risk for passing the disorder to your childrens.
Doctors diagnose thalassemias using blood tests, including a complete blood count (CBC) and special hemoglobin tests.
A CBC measures the amount of hemoglobin and the different kinds of blood cells, such as red blood cells, in a sample of blood. People who have thalassemias have fewer healthy red blood cells and less hemoglobin than normal in their blood. People who have alpha or beta thalassemia trait may have red blood cells that are smaller than normal.
Hemoglobin tests measure the types of hemoglobin in a blood sample. People who have thalassemias have problems with the alpha or beta globin protein chains of hemoglobin.
Moderate and severe thalassemias usually are diagnosed in early childhood. This is because signs and symptoms, including severe anemia, often occur within the first 2 years of life.
People who have milder forms of thalassemia might be diagnosed after a routine blood test shows they have anemia. Doctors might suspect thalassemia if a person has anemia and is a member of an ethnic group that's at increased risk for thalassemias. (For more information, go to "Who Is at Risk for Thalassemias?")
Doctors also test the amount of iron in the blood to find out whether the anemia is due to iron deficiency or thalassemia. Iron-deficiency anemia occurs if the body doesn't have enough iron to make hemoglobin. The anemia in thalassemia occurs because of a problem with either the alpha globin or beta globin chains of hemoglobin, not because of a lack of iron.
Because thalassemias are passed from parents to children through genes, family genetic studies also can help diagnose the disorder. These studies involve taking a family medical history and doing blood tests on family members. The tests will show whether any family members have missing or altered hemoglobin genes.
If you know of family members who have thalassemias and you're thinking of having children, consider talking with your doctor and a genetic counselor. They can help determine your risk for passing the disorder to your children.
If you're expecting a baby and you and your partner are thalassemia carriers, you may want to consider prenatal testing.
Prenatal testing involves taking a sample of amniotic fluid or tissue from the placenta. (Amniotic fluid is the fluid in the sac surrounding a growing embryo. The placenta is the organ that attaches the umbilical cord to the mother's womb.) Tests done on the fluid or tissue can show whether your baby has thalassemia and how severe it might be.