Type of disease: Rare conditions
Alpha-thalassemia is a blood disorder that reduces the body's production of hemoglobin. Affected individuals have anemia, which can cause pale skin, weakness, fatigue, and more serious complications. Two types of alpha-thalassemia can cause health problems: the more severe type is known as Hb Bart syndrome; the milder form is called HbH disease. Hb Bart syndrome may be characterized by hydrops fetalis; severe anemia; hepatosplenomegaly; heart defects; and abnormalities of the urinary system or genitalia. Most babies with this condition are stillborn or die soon after birth. HbH disease may cause mild to moderate anemia; hepatosplenomegaly; jaundice; or bone changes. Alpha-thalassemia typically results from deletions involving the HBA1 and HBA2 genes. The inheritance is complex, and can be read about here. No treatment is effective for Hb Bart syndrome; for HbH disease, occasional red blood cell transfusions may be needed. Source: Genetic and Rare Diseases Information Center (GARD), supported by ORDR-NCATS and NHGRI.