or Brit  thal*as*sae*mia  n :  any of a group of inherited hypochromic anemias and esp. Cooley's anemia controlled by a series of allelic genes that cause reduction in or failure of synthesis of one of the globin chains making up hemoglobin and that tend to occur esp. in individuals of Mediterranean, African, or southeastern Asian ancestry - called also Mediterranean anemia  - sometimes used with a prefix (as alpha-, eta-, r delta-) to indicate the hemoglobin chain affected - see BETA THALASSEMIA  .
 
 
 
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