Beta-thalassemia

one of two principal protein components of adult hemoglobin

Description
The majority of adult hemoglobin contains two types of protein subunits, alpha globin and beta globin. Defects in the beta globin chain lead to beta thalassemia, with the general complications of thalassemia and beta-thalassemia specific features. Beta globin is encoded by the HBB gene, and therefore by two functional copies in the human diploid (containing a set of duplicate chromosomes) genome. Defects in both gene copies results in beta thalassemia major (also called Cooley's anemia) with anemia, kidney enlargement and, if untreated, death before the age of twenty. Defects in one gene copy produce beta thalassemia minor (also called beta thalassemia trait) and carrier status, with mild or no symptoms. Different kinds of defects can modify the severity of the disease, and thalassemia intermedia describes patient conditions between the typical major and carrier phenotypes. See thalassemia, heterozygous, homozygous