Beta Thalassemia

Beta Thallasemia Beta Thalassemia Beta thalassemia is the severer of the two main types of thalassemia -- an inherited blood disease resulting from defective production of hemoglobin. About 100,000 people are born worldwide every year with beta thalassemia which occurs most frequently in people of Italian, Greek, Middle Eastern, Southern Asian and African Ancestry. (Learning about...," 2004) People with beta thalassemia usually develop anemia, resulting in inadequate delivery of oxygen to the body's tissues and it proves fatal in most cases, if left untreated.

In this paper we shall discuss the disease develops; the types of beta thalassemia, how it is inherited, its symptoms, diagnosis and treatment. How Beta Thalassemia develops? Hemoglobin, the protein that transports oxygen in the blood, is made up of four chains of amino acids: two identical alpha chains and two identical beta chains. Thalassemia is the result of an imbalance in the production of beta chains that is caused by a mutation in the genes that direct their production.

A mutation to the beta genes decreases the production of beta chains, resulting in beta thalassemia. Types of Beta Thelassemia There are two forms of beta thalassemia: thalassemia minor and thalassemia major (which is also called Cooley's anemia after the physician who first discovered the disease). Thalassemia minor occurs in a person who has only one copy of the beta thalassemia gene (together with one perfectly normal beta-chain gene). It causes only mild anemia and normally no treatment is necessary for the affliction.

A person with Thalassemia major (Cooley's anemia) has two genes for beta thalassemia and no normal beta-chain gene causing a severe deficiency in beta chain production. It is a serious disease and proves fatal, if left untreated. ("Beta Thalassemia" Medicine.net, 2004) How is Beta Thelassemia Inherited? Each person has two copies of the beta gene, one inherited from each parent. Beta thalassemia results when both copies of the beta gene are abnormal.

A person with only one abnormal copy of the beta gene does not develop the disease but is a carrier of beta thalassemia. When two carriers of beta thalassemia have children, each child has a 25% chance of inheriting two abnormal copies of the beta gene and, therefore, developing the disease. Each child has a 50% chance of inheriting one abnormal gene and being a carrier, and a 25% chance of inheriting two normal beta genes.

A carrier of beta thelassamia does not develop any symptoms of the disease but can pass on the disease to their children. (Nathan and Nisbet-Brown, 2003) Symptoms An infant born with beta thalassemia initially appears normal, but within a few months the baby becomes anemic and develops symptoms such as poor growth, irritability, fatigue, and sometimes jaundice -- a yellow discoloration of the skin that results from excessive destruction of red blood cells.

As the child's body attempts to correct the anemia, production of red blood cells increases in the bone marrow. But these new red cells are destroyed almost as quickly as they are produced because they too are abnormal. Eventually, the bone marrow expands, causing bones to become thin and weak, and the child suffers repeated fractures. The expansion of the marrow also changes the shape of the bones, stunting the child's growth and distorting the shape of the head and face.

The liver and spleen become greatly enlarged because red cell production also occurs in these organs. In addition children with beta thalassemia are prone to infections. If untreated, beta thalassemia is usually fatal within a few years mainly due to lack of oxygen that damages various organs in the body, and most patients die of heart failure. (Ibid.) Diagnosis Symptoms such as poor growth and enlargement of the liver and spleen are the first signs that a child may have thalassemia.

However, for a firm diagnosis, a doctor usually performs several types of blood tests and examines the family medical history of the patient. A blood count is taken that reveals the number of red cells present -- a low count being indicative of anemia. A technique known as hemoglobin electrophoresis is used by doctors to isolate different types of hemoglobin in a patient's blood, and distinguish between normal individuals, carriers, and thalassemia patients.

The method is also used to test a child's parents and if it is established that both are carriers; it helps to confirm the diagnosis. ("Beta Thellasemia," Child Health, 2001) Recently, prenatal diagnosis of thalassemia has become possible through procedures such as amniocentesis and chorionic villus sampling. This enables couples the choice of aborting affected fetuses. It is also now possible to pinpoint the type of thalassemia mutation afflicting a patient, which allows doctors to predict the severity of the patient's disease.

(Nathan, 2003) Treatment Frequent blood transfusions keep the hemoglobin levels near normal but repeated blood transfusions lead to iron overload that can damage the heart,.