Thalassemia
(Cooley's Anemia; Mediterranean Anemia; Thalassemia Major and Minor)
Thalassemia refers to a group of inherited blood disorders in which the body's bone marrow is unable to form normal amounts of hemoglobin, the oxygen-carrying pigment in red blood cells. People of Mediterranean, African, and Southeast Asian origin are most commonly affected.
Thalassemia is classified as alpha or beta, with each type displaying varying degrees of severity depending upon the number of genes that are inherited. In the most severe form -- beta thalassemia major, or Cooley's anemia -- a child inherits the causative gene from both parents. At birth, such an infant appears normal, but severe anemia develops during the first few months of life. These babies grow slowly and are thin and jaundiced. They are likely to develop a variety of skeletal abnormalities and enlargement of the heart, liver, and spleen. Most will die before reaching adulthood, although advances in treatment are extending survival.
Children who inherit only one of the beta thalassemia genes become carriers. They usually do not develop anemia even though their blood cell counts and hemoglobin may be slightly atypical.
Normally, a person inherits four alpha globin genes, two from each parent. If one is missing, the child will be an asymptomatic carrier of alpha thalassemia. Two missing genes result in some blood abnormalities, but anemia and other health consequences are unlikely. Someone with only one alpha gene has more pronounced abnormalities; a complete absence results in a fatal syndrome called hydrops fetalis.
Diagnostic Tests and Procedures
The primary diagnostic test is a blood smear to look for abnormal red blood cells. Other blood tests may be ordered, as well as X-rays to see if there are skeletal abnormalities indicating bone thinning and overactive bone marrow.
People who have a family history of thalassemia can be tested for the genetic trait. Problems generally occur only if both parents are carriers, in which case genetic counseling may be advisable when planning a family. Beta thalassemia can often be diagnosed before birth through amniocentesis or chorionic villi sampling (CVS) -- tests in which the DNA in cells shed from the fetus is analyzed. If the results indicate possible thalassemia, analysis of a sample of fetal blood can confirm it.
Medical Treatments
Genetic carriers and people with asymptomatic thalassemia minor do not need treatment, but children with the major form require periodic transfusions of red blood cells. Frequency varies according to the severity of the disease and local medical practice. In I most areas, moderate transfusions are I given every three to four weeks. As a child grows, more red blood cells must be given with each transfusion.
Although transfusions control the anemia and allow for more normal growth and development, they create new problems for thalassemia patients. Even with proper screening and tests, transfusions carry a slight risk of transmission of hepatitis, HIV, and other blood-borne diseases. Also, repeated transfusions produce a buildup of excess iron in the body, which can damage the heart, liver, and other organs. Therefore, thalassemia patients must usually undergo treatment with deferoxamine (Desferal), a chelating drug that binds to excess iron and is then excreted. The drug is dripped into the body by way of a special pump for 8 to 12 hours, usually during sleep.
Researchers are working on oral chelating drugs that can eliminate the need for desferoxamine treatment. Another drug under study is phenylbutyraie, commonly used for rare metabolic disorders, which appears to increase hemoglobin production.
An enlarged spleen, which destroys excessive numbers of red blood cells, lessens the effectiveness of transfusions. In such cases, it may be best to remove the spleen. Because spleen removal lowers immunity, doctors recommend immunization against pneumonia beforehand. Some also prescribe preventive antibiotics for patients who have had a splenectomy.
Alternative Therapies
Nutrition Therapy. People with thalassemia should avoid foods that are rich in iron or fortified with the mineral;they may need folic-acid supplements to aid in making red blood cells. Those being treated with deferoxamine may require extra vitamin C. However, no-supplements of any kind should be taken without a doctor's supervision.
Self-Treatment
Children with thalassemia should be encouraged to attend school regularly, engage in suitable activities, and live as normal a life as possible. If transfusion are given on weekends or in the late afternoon or evening, then treatment will not interfere with the youngsters normal school day.
Barring a serious problem, thalassemic children can usually participate in sports, but they should avoid overexertion. As these children enter their teens and come to realize their high risk of premature death, psychological counseling or a self-help group may enhance their ability to cope.
Traveling to high altitudes can cause problems for people with thalassemia. They should either avoid altitudes above 11,000 feet or have a transfusion immediately before ascending. In such cases, the stay should not last more than a week.
Other Causes of Anemia
Iron deficiency is the most common cause of anemia. Other nutritional deficiencies, autoimmune diseases, genetic disorders, and bleeding disorders can also produce anemia.