<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>A group of hereditary hemolytic anemias in which there is decreased synthesis of one or more hemoglobin polypeptide chains. There are several genetic types with clinical pictures ranging from barely detectable hematologic abnormality to severe and fatal anemia.</n0:def-definition><n0:def-source>MSH2003_2003_05_12</n0:def-source></n0:ComplexDefinition>
<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>An inherited blood disorder characterized by a decreased synthesis of one of the polypeptide chains that form hemoglobin. Anemia results from this abnormal hemoglobin formation.</n0:def-definition><n0:def-source>NCI</n0:def-source></n0:ComplexDefinition>