What is thalassemia?
Thalassemia is an inherited disorder that affects normal hemoglobin synthesis. Hemoglobin is present within healthy red blood cells and transports oxygen to the body’s tissues. Hemoglobin is produced in the bone marrow by red blood cells. In thalassemia, the body does not make enough hemoglobin or the hemoglobin it makes is abnormal. In turn, this causes red blood cells to be too small, abnormally shaped, and prone to rupture—or hemolysis. The ultimate result is anemia due to a lack of normal red blood cells.
Children inherit thalassemia in an autosomal recessive pattern. This means a child will only have the disease if both parents pass along a defective gene. A child will be a carrier, but not have symptoms or only mild symptoms, if only one parent passes the gene. However, certain forms of the disease have a more complicated genetic picture because more than one gene can cause it.
Thalassemia is a rare disease, affecting 4 to 5 out of every 10,000 births worldwide. It is most common in people from Africa, Asia, and Mediterranean or Middle Eastern countries, or people with these ancestries. It occurs in both sexes equally.
Typically, thalassemia symptoms are either present at birth or develop within the first two years of life. Carriers of the disease may not have any symptoms. The symptoms, and their severity, will vary with the number of defective genes. Most often, symptoms relate to anemia and include fatigue, weakness, and shortness of breath. With severe forms, other symptoms can be present, such as jaundice and slow growth.
Thalassemia treatment is not always necessary. People with mild disease may be able to manage without treatment. With more severe disease, regular blood transfusions are necessary. In some cases, a stem cell transplant is effective in treating the disease and eliminating the need for transfusions.
Left untreated, thalassemia can lead to organ damage within a short period of time. See your child’s doctor promptly if you notice symptoms of anemia or problems with your child’s growth.
What are the different types of thalassemia?
There are several terms that describe thalassemias. Some relate to the severity—trait, minor, intermedia and major. Trait and minor generally mean the person is a carrier (they have the genetic trait, or characteristic) and has no symptoms or very mild symptoms. Intermedia refers to mild to moderate anemia symptoms, which may accompany other health problems. With intermedia disease, transfusions improve a person’s quality of life. Major thalassemia means the disease is severe and transfusions are necessary to live.
There are also terms that describe the thalassemia types. These terms relate to the specific hemoglobin protein that is abnormal. Normal hemoglobin has two pairs of protein chains—a pair of alpha chains and a pair of beta chains. A mutation in either of these chain pairs can result in thalassemia. Although they have similar symptoms, they are named for the affected chain—alpha thalassemia and beta thalassemia.
The most severe form of alpha thalassemia is also called hydrops fetalis. It usually results in stillbirth or death shortly after birth. The most severe form of beta thalassemia is also called Cooley’s anemia. It is named for the physician who first described it.
What are the symptoms of thalassemia?
Thalassemia symptoms vary in severity, ranging from no or mild symptoms to severe and life-threatening symptoms.
Common symptoms of thalassemia
Common symptoms of thalassemia include:
Abdominal swelling, fullness or discomfort
Jaundice, or yellowing of the skin and eyes
- Slow growth, facial bone deformities, and delayed puberty
Thalassemia is a serious disease that can eventually become life-threatening in severe cases. Make an appointment with your child’s doctor if you notice any symptoms of thalassemia.
What causes thalassemia?
DNA mutations are the cause of thalassemia. These mutations cause the proteins in hemoglobin to develop abnormally or in too little an amount. This results in red blood cells that are not formed right and cannot carry a normal amount of oxygen.
The mutations that cause thalassemia are hereditary. Parents pass them to their children. The number of abnormal genes determines the severity of the disease.
There are two sets of genes—HBA1 and HBA2—that make the alpha protein chain of hemoglobin. Children get one copy of each gene from each parent, making a total of four genes. So, the following abnormalities are possible:
One mutated gene will not cause disease, but makes you a carrier.
Two mutated genes will likely cause mild symptoms.
Three mutated genes will cause moderate to severe disease.
- Four mutated genes, which is rare, usually causes stillbirth or death shortly after birth.
There is one set of genes—HBB—that makes the beta protein chain of hemoglobin. The affected child gets one copy from each parent, making the following abnormalities possible:
One mutated gene makes you a carrier who may or may not have mild symptoms.
- Two mutated genes will likely cause moderate to severe symptoms.
What are the risk factors for thalassemia?
Thalassemia is a hereditary disease. People most likely to have the genetic abnormality come from or have ancestry in African, Asian, or Mediterranean or Middle Eastern countries.
The risk of passing on alpha thalassemia is complex because two sets of genes play a role. In general, if both parents have a gene mutation, their children are at risk of thalassemia.
For beta thalassemia, the risk of inheriting the disease is more straightforward. If one parent has beta thalassemia, each child will be a carrier. If one parent is a carrier, each child has a 50% chance of also being a carrier. If both parents are carriers, each child has a 25% chance of having the disease, a 50% chance of being a carrier, and a 25% chance of not having the disease and not being a carrier.
Reducing your risk of thalassemia
Because it is genetic, it is not possible to prevent thalassemia. If you have the disease or know you are a carrier, talk with your doctor about genetic counseling. Working with a genetic counselor is the best way to understand the risk to future children. This healthcare provider is a resource to help you sort through the complex issues about the decision to have children or not.
What are the diet and nutrition tips for thalassemia?
Your doctor may have several dietary recommendations for managing thalassemia. In addition to eating a healthy, balanced diet, your doctor may advise the following:
Avoid extra iron, including multivitamins containing iron
Eat foods high in calcium and vitamin D. Some people may need supplements.
- Take a folic acid supplement.
Ask your healthcare provider for guidance before making significant changes to your diet or starting a supplement.
How do doctors diagnose thalassemia?
In most cases, signs and symptoms of thalassemia appear in the first two years of life. However, people with mild disease that does not cause symptoms may find out they have thalassemia after routine blood tests reveal a minor anemia or red blood cell abnormality.
To diagnose thalassemia, your child’s doctor will take a thorough medical history, perform an exam, and order testing.
Questions your child’s doctor may ask include:
How often do you notice these symptoms: all the time or just occasionally?
How severe are your child’s symptoms?
What, if anything, seems to make your child’s symptoms better or worse?
- Does your family have a history of blood or bone marrow disorders?
During the exam, the doctor will look for signs and symptoms of anemia and other problems, such as jaundice. Feeling the abdomen may reveal an enlarged spleen or liver.
To confirm a thalassemia diagnosis, blood tests are necessary including:
CBC (complete blood count) and peripheral smear to examine blood cells under a microscope
Hemoglobin electrophoresis to detect abnormal hemoglobin proteins
- Mutational analysis to examine hemoglobin genes
Prenatal testing can detect thalassemia before birth. Tests include amniocentesis and chorionic villus sampling.
What are the treatments for thalassemia?
Most people with mild disease do not require treatment. They are usually able to manage mild symptoms with lifestyle changes, such as healthy eating, exercise and sleep habits. People with moderate to severe disease will need treatment.
Standard thalassemia treatments include:
Blood transfusions: This treatment gives people healthy donor red blood cells to carry oxygen to their tissues. The severity of the disease will determine how often regular blood transfusions are necessary. Severe disease may require transfusions every few weeks.
Chelation therapy: Frequent transfusions can cause iron to build up in the blood. Too much iron can damage the heart and other organs. To manage this, doctors use drugs to remove the extra iron. Oral drugs include deferasirox (Exjade, Jadenu) and deferiprone (Ferriprox). Sometimes, doctors use an injectable drug, deferoxamine (Desferal).
Luspatercept (Reblozyl): This biologic can reduce the need for transfusions in people with beta thalassemia.
- Stem cell transplant: This treatment replaces diseased stem cells with healthy donor ones. Stem cells are cells in the bone marrow that develop into all the different types of blood cells, including red blood cells. This treatment may help children with severe disease avoid lifelong blood transfusions. This is the only possible cure for thalassemia at this time.
The healthy spleen normally traps and destroys abnormal red cells, as happens continuously in thalassemia. Sometimes, doctors recommend removing the spleen if it is enlarged. This is a splenectomy.
What are the potential complications of thalassemia?
Several complications are possible with thalassemia including:
Bone deformities and fractures: Thalassemia can cause the bone marrow to expand, which enlarges the bones. It especially affects the bones of the face and skull, causing deformities. The bone structure also becomes thinner and more brittle—a condition called osteoporosis. This makes bones more prone to fractures.
Enlarged spleen: The spleen is responsible for clearing out old or damaged blood cells. So, it works overtime in thalassemia and can become enlarged. An enlarged spleen can interfere with treatment and make anemia worse. If this happens, the doctor may recommend removing it (splenectomy).
- Infections: People with thalassemia are at increased risk of infection. The risk is higher after removal of the spleen, as this organ also helps fight infections.
Does thalassemia shorten life expectancy?
In general, mild to moderate thalassemia does not affect a person’s life expectancy. Severe disease can shorten survival. Early deaths are usually due to heart failure from iron overload. This emphasizes the importance of following your chelation therapy treatment plan. For some people, a bone marrow transplant can eliminate the need for transfusions and cure thalassemia.