By Medifit Education.
Thalassemia is a genetic blood disorder. People with Thalassemia disease are not able to make enough hemoglobin, which causes severe anemia. Hemoglobin is found in red blood cells and carries oxygen to all parts of the body. When there is not enough hemoglobin in the red blood cells, oxygen cannot get to all parts of the body. Organs then become starved for oxygen and are unable to function properly.
TYPES OF THALASSEMIA
There are two primary types of Thalassemia disease:
Alpha Thalassemia disease and Beta Thalassemia disease.
Beta Thalassemia Major (also called Cooley’s Anemia) is a serious illness. Symptoms appear in the first two years of life and include paleness of the skin, poor appetite, irritability, and failure to grow. Proper treatment includes routine blood transfusions and other therapies.
Alpha Thalassemia Major is a very serious disease in which severe anemia begins even before birth. Pregnant women carrying affected fetuses are themselves at risk for serious pregnancy and delivery complications. Another type of Alpha Thalassemia is Hemoglobin H disease. There are varying degrees of Hemoglobin H disease.
Thalassemia is a complex group of diseases that are relatively rare in the United States but common in Mediterranean regions and South and Southeast Asia. Worldwide, there are 350,000 births per year with serious hemoglobinopathies (blood disorders). In the United States, as a consequence of immigration patterns, occurrence of thalassemia disorders is increasing.
DISTRIBUTION OF DISEASE IN WORLD
The thalassemias are a diverse group of genetic blood diseases characterized by absent or decreased production of normal hemoglobin, resulting in a microcytic anemia of varying degree. The thalassemias have a distribution concomitant with areas where P. falciparum malaria is common. The alpha thalassemias are concentrated in Southeast Asia, Malaysia, and southern China. The beta thalassemias are seen primarily in the areas surrounding Mediterranean Sea, Africa and Southeast Asia. Due to global migration patterns, there has been an increase in the incidence of thalassemia in North America in the last ten years, primarily due to immigration from Southeast Asia.
In the normal adult, hemoglobin A, which is composed of two alpha and two beta globins (A2Β2), is the most prevalent, comprising about 95% of all hemoglobin. Two minor hemoglobins also occur: hemoglobin A2, composed of two alpha and two delta globins (α2 δ2) comprises 2-3.5% of hemoglobin, while hemoglobin F, composed of two alpha and two gamma globins (α2 γ2) comprises less than 2% of hemoglobin.
Hemoglobin F, or fetal hemoglobin, is produced by the fetus in utereo and until about 48 weeks after birth. Hemoglobin F has a high oxygen-affinity in order to attract oxygen from maternal blood and deliver it to the fetus. After birth, the production of adult hemoglobin rapidly increases and fetal hemoglobin production drops off.
Thalassemia is a blood disorder passed down through families (inherited) in which the body makes an abnormal form of hemoglobin, the protein in red blood cells that carries oxygen. The disorder results in excessive destruction of red blood cells, which leads to anemia. Anemia is a disorder in which your body doesn’t have enough normal, healthy red blood cells (RBC).
This disease is inherited, meaning that at least one of your parents must be a carrier of the disease. It is caused by either a genetic mutation, or a deletion of certain key genes.
The two main forms of thalassemia are alpha thalassemia and beta thalassemia. In alpha thalassemia, at least one of the alpha globin genes has a mutation or abnormality. In beta thalassemia, the beta globin genes are the ones affected.
Each of these two forms of thalassemia has several distinct types. The exact form you have will affect the severity of your symptoms and your prognosis.
CAUSES AND RISK FACTORS FOR THALASSEMIA
Thalassemia occurs when there is an abnormality or mutation in one of the genes involved in hemoglobin production. This genetic defect is inherited from your parents.
If only one of your parents is a carrier for thalassemia, you may develop a form of the disease called “thalassemia minor.” If this occurs, you will probably not have symptoms, but you will be a carrier of the disease. Some people with thalassemia minor do develop minor symptoms.
If both of your parents are carriers of thalassemia, you have a 25 percent chance of inheriting a more serious form of the disease.
Thalassemia is most common in people from Southeast and Central Asia, the Mediterranean, the Middle East, India, and North Africa.
WHAT ARE THE SYMPTOMS OF THALASSEMIA?
- The symptoms of thalassemia depend on which type you have.
Thalassemia minor usually does not cause any symptoms. If it does, it causes only minor anemia.
Beta thalassemia comes in two serious types: thalassemia major (also called Cooley’s anemia) and thalassemia intermedia.
The symptoms of thalassemia major (Cooley’s anemia) generally appear before a child’s second birthday. The severe anemia related to this condition can be life-threatening.
Other symptoms include:
- frequent infections
- poor appetite
- failure to thrive
- jaundice (yellowing of the skin and whites of the eyes)
- enlarged organs
This form of thalassemia is usually so severe that it requires regular blood transfusions.
Thalassemia intermedia is a less severe form of beta thalassemia. While people with this condition still have anemia, they do not need blood transfusions.
Alpha thalassemia also has two serious types: hemoglobin H disease and hydrops fetalis.
Hemoglobin H disease can cause bone issues. The cheeks, forehead, and jaw may all overgrow. In addition to the bone issues and the anemia associated with any kind of thalassemia, hemoglobin H disease can cause these other symptoms:
- extremely enlarged spleen
Hydrops fetalis is an extremely severe form of thalassemia. It occurs before birth, and most individuals with this condition are either stillborn or die shortly after being born.
HOW IS THALASSEMIA DIAGNOSED?
A doctor who is trying to diagnose thalassemia will typically take a blood sample. It will be tested for anemia and for abnormal hemoglobin. A lab technician will also look at the blood under a microscope to see if the red blood cells appear misshapen. Abnormally shaped red blood cells are a symptom of thalassemia. Another test may be performed called hemoglobin electrophoresis. This test separates out the different molecules in the red blood cells, allowing the abnormal type to be identified.
Depending on the type and severity of the thalassemia, a physical examination might also help in the diagnosis. For example, a severely enlarged spleen might suggest to your doctor that you have hemoglobin H disease.
HOW IS THALASSEMIA TREATED?
The treatment for thalassemia depends on the type and severity of disease involved. Your doctor will give you a course of treatment that is customized to your particular case.
In general, treatments you may receive include:
- blood transfusions
- bone marrow transplant
- medications and supplements
- possible surgery to remove the spleen and/or gallbladder
You may be instructed not to take vitamins or supplements containing iron. This is especially true if you require blood transfusions. People who receive blood transfusions receive extra iron that the body can’t easily get rid of and iron can accumulate in tissues, which can be potentially fatal.
If you are receiving a blood transfusion, you may also need chelation therapy, which generally involves receiving an injection of a chemical that binds with iron (and other heavy metals). This helps remove extra iron from your body.
WHAT IS THE LONG-TERM OUTLOOK FOR THALASSEMIA?
The prognosis for thalassemia depends on the type of the disease involved. Hydrops fetalis, for example, is usually fatal either before or shortly after birth.
On the other hand, people who have mild or minor forms of thalassemia can typically lead normal lives.
Other forms of thalassemia can fall anywhere in between. In severe cases, heart failure may occur in the 20s.
Your doctor can give you more information about your personal prognosis, as well as how your treatments can help improve your life or increase your expected lifespan.
By Medifit Education.