Thalassemia is an inherited condition that causes hemoglobin, the substance that carries oxygen in the red blood cells, to be formed defectively. This, in turn, leads to anemia, which is a low red blood cell count.
Thalassemia is an inherited condition that causes hemoglobin, the substance that carries oxygen in the red blood cells, to be formed defectively. This, in turn, leads to anemia, which is a low red blood cell count.
Thalassemia is an inherited disorder that comes in two forms - alpha and beta. An individual carries four genes for the alpha globin portion of hemoglobin, two from each parent. The severity of alpha thalassemia depends on how many genes are affected. If only one gene is affected, the individual is a silent carrier. Involvement of two genes results in a mild anemia; three involved genes mean a severe anemia, and an individual with all four genes affected will usually not survive infancy.
A person carries only two genes for the beta globin. One affected beta gene causes a mild anemia; both affected beta genes results in a severe anemia known as "Cooley's anemia".
An individual with three or four alpha genes affected, or both beta genes affected (thalassemia major), usually has severe hemolytic disease. This means that the red blood cells are constantly being destroyed, faster than the body can replace them. Thalassemia major is usually diagnosed by 1 year of age.
The symptoms of thalassemia major may include: fatiguepalenessjaundice, or yellow colored skinfailure to thrive, in infancy enlarged spleen and liverbony abnormalities, especially of the facial bones
Thalassemia is a relatively common genetic disease. It is more common in people of African, Mediterranean, and Asian heritage.
There is no way to prevent thalessemia once the child is born. Genetic counseling may be helpful to couples with a family history of the disease. In beta thalassemia, there is a 25% chance with each pregnancy that a child will be born with thalassemia major if both parents carry the gene for thalassemia. The probabilites with alpha thalassemia are slightly more complex, and depend on how many abnormal genes each parent has.
Thalassemia minor usually does not cause long-term problems. Thalassemia major, however, can result in stunted growth, problems in bone development, darkened skin, and ultimately, premature death.
Thalassemia minor usually does not cause long-term problems. Thalassemia major, however, can result in stunted growth, problems in bone development, darkened skin, general growth problems, and death.
Thalassemia is an inherited condition, so a person can passed it on to his or her children.
With severe thalassemia, regular blood transfusions are needed. The person will also require folic acid and other nutritional supplements. An individual who has frequent red blood cell transfusions can develop iron overload. This can be avoided with chelation therapy, a process that removes excess iron from the body. This therapy may need to be started early in childhood.
Sometimes, a suitably matched bone marrow donor can be found for a person with thalassemia. In this case, a bone marrow transplant can cure the condition, if the individual survives the process.without succumbing to infection or bleeding.
Gene therapy, in which investigators attempt to insert the gene for normal hemoglobin into the individual's marrow stem cells, is being researched. In addition, the injection of medications known as growth factors, that stimulate the bone marrow to make more blood, is being tested in clinical trials.
These approaches are intended to benefit those with severe thalassemia.
Frequent blood transfusions can lead to an iron overload. Excess iron can end up in various body tissues and cause skin discoloration, liver disease, and diabetes. Chelation, which involves giving an iron-binding agent daily, orally or by injection, can help eliminate the excess iron from the body.
Blood transfusions can be complicated by allergic reactions. With today's screening procedures employed in blood banks, the risks of hepatitis, HIV, and other infections from transfusion have been essentially eliminated.
Bone marrow transplants can cause the body to attack the new bone marrow. Rarely, the new bone marrow may not function at all.
A person with severe thalassemia may need frequent blood transfusions or injections for the rest of his or her life.
Thalassemia is monitored by frequent blood tests. The person will need to be followed closely by the healthcare professional, to whom any new or worsening symptoms should be reported.
Black JM. Matassarin-Jacobs E.: Medical-surgical nursing: clinical management for continuity of care. ed 5; ch 53; p 1482-3. Philadelphia, 1997, W.B. Saunders.
Isselbacher KJ, Braunwald E, Wilson, JD, et al: Harrison's principles of internal medicine. ed 13; p 1901-1904. New York, 1994, McGraw-Hill.
Martin MB. Butler RB. Understanding the basics of beta thalassemia major. Pediatric Nursing. 19(2): 143-5, 1993 Mar-Apr.
The Merck Manual of Medical Information, 1997
Professional Guide to Diseases: 6th edition, 1998
