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In which regions of the world has thalassemia been especially common?
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blood disease
Peripheral blood smear revealing histopathologic features indicative of a blast crisis in a case of chronic myelogenous leukemia (CML). Blast crisis occurs when one-fifth to one-third of the cells in the blood or bone marrow are immature blood cells, or blast cells. This phase of CML is characterized by fever, weakness, and an enlarged spleen.
Thalassemia is a group of inherited blood disorders characterized by a deficiency of hemoglobin. While the genes for these conditions are distributed globally, they are most frequently found in populations with ancestry from the following regions:
- The Mediterranean: The disorder was first identified among peoples living around the Mediterranean Sea, where its incidence remains high.1
- The Middle East: This region is a primary area where thalassemia genes are commonly found.1
- Southern and Southeastern Asia: These areas also have a high prevalence of the condition among their populations.12
Additionally, thalassemia has been identified in some northern European and Native American populations. Among individuals of African descent, the disease typically presents in an unusually mild form. It is believed that the thalassemia gene persists in these populations because, in its heterozygous state, it may offer some protection against malaria.12