Thalassemias is the name for the group of genetic blood diseases which vary widely in severity.
As frightening as thalassemias can be, the outlook is encouraging. In the past 20 years, new therapies have greatly improved the quality of life and life expectancy in kids who are diagnosed with this disease.
What Is Thalassemia?
Thalassemia is a genetic disorder that involves the decreased and defective production of hemoglobin, a molecule that's found inside all red blood cells and is necessary to transport oxygen throughout the body.
Hemoglobin contains two different kinds of protein chains named alpha and beta chains. Any deficiency in these chains causes abnormalities in the formation, size, and shape of red blood cells.
There are two types of thalassemia: alpha-thalassemia and beta-thalassemia. Their names describe which part of the hemoglobin molecule that is effected, the alpha or the beta chain.
Thalassemia can cause ineffective production of red blood cells, and the destruction of red blood cells. As a result, people with thalassemia often have a reduced number of red blood cells in the bloodstream, a condition called anemia, which can affect the transportation of oxygen to the body tissues that need it. In addition, thalassemia can cause red blood cells to be smaller than normal, or the amount of hemoglobin in the red blood cells to be below normal levels.
Kids who have with different forms of thalassemia have different kinds of health problems resulting from the disorder. Some children only have mild anemia with little or no effects, while others require frequent serious medical treatment.
What Causes Thalassemia?
Thalassemia is always inherited, passed on from parents to children through their genes. A child cannot develop the disease unless both parents carry the thalassemia gene.
If only one parent passes the gene for thalassemia on to the child, then the child is said to have thalassemia trait. Thalassemia trait will not develop into the full-blown disease, and no medical treatment is necessary. Many families have thalassemia carriers, but the trait often goes undiagnosed because the trait produces no or few symptoms. Frequently, thalassemia is not diagnosed in a family until a baby is born with the disease. So if someone in your family carries the gene, it's a good idea to have genetic counseling when you're thinking of having children.
At one time it was believed that the disease affected only people of Italian or Greek descent. It is now known that in addition to people living in areas on the Mediterranean Sea (Italy, Greece, and Turkey), many people with thalassemia also come from or are descended from Africa, Malaysia, China, and many parts of Southeast Asia.
Because of a recent pattern of migration from Southeast Asia, there has been an increase in the past decade of thalassemia in North America. Testing for thalassemia is generally recommended for anyone from Southeast Asia with unexplained anemia. If your healthcare providers determine that your child is at risk for being affected by thalassemia, there are prenatal tests that you can have to find out if your unborn child is affected by the disease.
Alpha-Thalassemia
Children with alpha-thalassemia trait do not have thalassemia disease. A specific blood test called a hemoglobin electrophoresis is used to screen for alpha-thalassemia trait and can be done in infancy. But often, diagnosis of alpha thalassemia is done only after other conditions are ruled out, after the parents are screened. The disease can be harder to detect in older children and adults.
Kids who have the alpha-thalassemia trait usually have no significant health problems, with the exception of possibly being mildly anemic. The anemia can cause slight fatigue.
The fatigue resulting from alpha-thalassemia trait is often mistaken for an iron deficiency.
Other cases of alpha-thalassemia resemble another form of the disorder, called beta-thalassemia intermedia (see next section). People with this form of alpha-thalassemia may require occasional blood transfusions during times of physical stress, like fevers or other illnesses, or at times when the anemia becomes severe enough to cause symptoms such as fatigue.
The most severe form of the disorder is called alpha-thalassemia major. This type is extremely rare, and women carrying fetuses with this form of thalassemia have a high incidence of miscarriage because the fetuses cannot survive.
Beta-Thalassemia
Beta-thalassemia, the most common form of the disorder seen in the United States, is grouped into three categories: beta-thalassemia minor (trait), intermedia, and major (Cooley's anemia). A person who carries the beta-thalassemia gene has a 25% (1 in 4) chance of having a child with the disease if his or her partner also carries the trait.
Beta-Thalassemia Minor (trait)
Beta-thalassemia minor often goes undiagnosed because kids with the condition have no real symptoms other than mild anemia. It is often suspected based on routine blood tests such as a complete blood count (CBC) and can be confirmed with a hemoglobin electrophoresis. No treatment is usually needed.
As with alpha-thalassemia trait, the anemia associated with this condition may be misdiagnosed as an iron deficiency.
Beta-Thalassemia Intermedia
Children with beta-thalassemia intermedia have varying effects from the disease - mild anemia might be their only symptom or they might require regular blood transfusions.
The most common complaint is fatigue or shortness of breath. Some children also experience heart palpitations, also due to the anemia, and mild jaundice, which is caused by the destruction of abnormal red blood cells that result from the disease. The liver and spleen may be enlarged, which can feel uncomfortable for a child. Severe anemia can also affect a child's growth.
Another symptom of beta-thalassemia intermedia can be bone abnormalities. Because the bone marrow is working overtime to make more red blood cells to counteract the anemia, children can experience enlargement of their cheek bones, foreheads, and other bones. Gallstones are also a frequent complication of thalassemia because of abnormalities in bile production that involve the liver and the gallbladder.
Some children with beta thalassemia intermedia may require a blood transfusion only occasionally. They will always have anemia, but may not need transfusions except during illness, medical complications, or later on during pregnancy.
Other children with this form of the disease require blood transfusions on a regular basis. In these kids, low or falling hemoglobin levels greatly reduce the blood's ability to carry oxygen to the body, resulting in extreme fatigue, poor growth, and facial abnormalities. Regular transfusions can help alleviate these problems. Sometimes, kids who have this form of the disease have their spleens removed.
Beta-thalassemia intermedia is often diagnosed in the first year of a child's life. Doctors may be prompted to test for it when a child has chronic anemia, or a family history of the condition. As long as it is diagnosed while the child is still doing well and has not experienced any serious complications, the disorder can be successfully treated and managed.
Beta-thalassemia Major
Beta-thalassemia major, which is also called Cooley's anemia, is a severe condition in which regular blood transfusions are necessary for the child to survive.
Although multiple lifelong transfusions save lives, they also cause a serious side effect: an overload of iron in the bodies of thalassemia patients. Over time, people with thalassemia accumulate deposits of iron in their bodies, especially in the liver, heart, and endocrine (hormone-producing) glands. The deposits eventually can affect the normal functioning of the heart, and liver, in addition to delaying growth and sexual maturation.
To minimize iron deposits in the body, people affected by the disease must undergo chelation (iron-removing) therapy for up to 12 hours a day with subcutaneous (under the skin) doses of the iron-binding agent. Researchers are working to develop an iron chelator, which can be given by mouth, but currently, none is available.
Chelation therapy is typically given 5 to 7 days a week and has been proven to prevent liver and heart damage from iron overload, allow for normal growth and sexual development in children with thalassemia, and increase life span. Iron concentrations in the body are monitored every few months. Sometimes liver biopsies are needed to get a more accurate picture of the body's iron load.
There are side effects of the chelation drug, which is called desferrioxamine, which can include visual impairment and hearing loss. Any children who receive chelation therapy are usually screened on a regular basis for such side effects.
Other risks associated with chronic blood transfusions for thalassemia major include blood-borne diseases like hepatitis B and C. Blood banks can usually screen for such infections, in addition to rarer infections such as HIV. In addition, kids who have many transfusons can develop allergic reactions that can prevent further transfusions and cause serious illnesses.
For kids and teens with thalassemia, adolescence can be a difficult time, particularly because of the amount of time required for transfusions and chelation therapy.
Recently, some children have successfully undergone bone marrow transplants to treat thalassemia major; however, this is considered only in cases of severely disabling thalassemia disease. There is considerable risk to bone marrow transplants: the procedure involves the destruction of all of the blood-forming cells in the child's bone marrow and repopulating the marrow space with donor cells that must match perfectly (the closest match is usually from a sibling). The procedure is usually done in children younger than 16 years of age who have no existing evidence of liver scarring or serious liver disease. Results have been highly encouraging so far, with disease-free survival in most patients.
Blood-forming stem cells taken from umbilical cord blood have also been successfully transplanted, and research using this technique is expected to increase. Currently bone marrow treatment is the only known cure for the disease.
Talking to Your Child's Doctor
If you know the thalassemia trait exists in your family, it's important to meet with your child's doctor, particularly if you notice any of the symptoms of thalassemia major - anemia, listlessness, or bone abnormalities - in your child. If you are thinking of having children, particularly if you have any thalassemia in your family, it's a good idea to speak with a genetic counselor to determine your risk of passing on the disease to any future children.
Updated and reviewed by: Robin Miller, MD
Date reviewed: July 2005
