Thalassemia

A genetic disorder characterized by a defect in one of the hemoglobin chains, which reduces its oxygen-carrying capacity.

Hereditary (autosomal recessive) form of anemia, occurring most often in people of Mediterranean origin, characterized by abnormal hemoglobin synthesis. Persons homozygous for the trait, inheriting it from both parents—“thalassemia major”—are severely affected in childhood with anemia, enlarged spleen, failure to thrive, iron accumulation in the tissues, respiratory difficulty, and retarded growth and development. There is no cure; treatment involves repeated transfusions. Persons heterozygous for the trait, inheriting it from only one parent—“thalassemia minor”—may have few or no symptoms. The disease can be detected prenatally through amniocentesis. Also called Cooley’s anemia.

A group of genetic blood disorders that affect the production of one of the protein chains that forms the hemoglobin molecule. Thalassemia exists in two types—alpha thalassemia and beta thalassemia—each of which’ is subdivided into three subtypes. Thalassemia minor, also called trait, is associated with a very mild anemia that cannot be corrected with iron supplements but has no other symptoms. Thalassemia intermedia causes moderately severe hemolytic anemia and requires regular medical care and occasional blood transfusions. Thalassemia major is a serious disease characterized by the inability to create enough normal hemoglobin to survive, calling for regular blood transfusions.

A hereditary blood disease, widespread in the Mediterranean countries, Asia, and Africa, in which there is an abnormality in the protein part of the hemoglobin molecule. The affected red cells cannot function normally, leading to anemia. Other symptoms include enlargement of the spleen and abnormalities of the bone marrow. Individuals inheriting the disease from both parents are severely affected (thalassemia major), but those inheriting it from only one parent are usually symptom-free. Patients with the major disease are treated with repeated blood transfusions. The disease can be detected by prenatal diagnosis, including amniocentesis.

A group of hereditary anemias occurring in populations bordering the Mediterranean and in Southeast Asia. Anemia is produced by either a defective production rate of the alpha or beta hemoglobin polypeptide chain or a decreased synthesis of the beta chain. Heterozygotes are usually asymptomatic. The severity in homozygotes varies according to the complexity of the inheritance pattern, but thalassemia may be fatal.