Medical Definition of Thalassemia major
Thalassemia major: The dire disease also known as beta thalassemia. The clinical picture of this form of anemia was first described in 1925 by the pediatrician Thomas Benton Cooley. Other names for the disease are Cooley's anemia and Mediterranean anemia. The term thalassemia was coined by the Nobel Prize winning pathologist George Whipple and the professor of pediatrics William Bradford at U. of Rochester because thalassa in Greek means the sea (like the Mediterranean Sea) + -emia means in the blood so thalassemia means sea in the blood. Thalassemia is not just one disease. It is a complex contingent of genetic (inherited) disorders all of which involve underproduction of hemoglobin, the indispensable molecule in red blood cells that carries oxygen. The globin part of normal adult hemoglobin is made up of 2 alpha and 2 beta polypeptide chains. In beta thalassemia, there is a mutation (change) in both beta globin chains leading to underproduction (or absence) of beta chains, underproduction of hemoglobin, and profound anemia. The gene for beta thalassemia is relatively frequent in people of Mediterranean origin (for example, from Italy and Greece). Children with this disease inherit one gene for it from each parent (and so are said to be homozygous for beta thalassemia). The parents are carriers (heterozygotes) with just one thalassemia gene, are said to have thalassemia minor, and are essentially normal. Their children affected with beta thalassemia seem entirely normal at birth (because at birth we still have predominantly fetal hemoglobin which does not contain beta chains) but the anemia emerges in the first few months of life and becomes progressively more severe leading to pallor and easy fatiguability, failure to thrive (grow), bouts of fever (due to infections) and diarrhea. Treatment based on blood transfusions is helpful but not curative. Gene therapy will, it is hoped, be applicable to this disease.Source: MedTerms™ Medical Dictionary
Last Editorial Review: 6/9/2016
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