Hemoglobin E diseases: hematological, analytical, and biosynthetic studies in homozygotes and double heterozygotes for alpha-thalassemia.
Two families with Hb E diseases are described. In the Laotian family S, three homozygous Hb E were found. In the Vietnamese family H, double heterozygous Hb E-alpha-thalassemia-2 and Hb E-Hb H diseases were found. Anemia or hemolysis was absent in Hb E carriers, unless complicated by iron deficiency, the presence of severe alpha-thalassemia gene (Hb H disease), or oxidative drug (paraaminosalicylic acid). Moreover, iron deficiency or concurrent alpha-thalassemia genes resulted in a decreased amount of Hb E in its heterozygous carriers. Mild microcytosis and hypochromia were observed in Hb E heterozygotes, whereas the microcytosis and hypochromia were more pronounced in Hb E homozygotes. Globin chain synthesis studies yielded unbalanced alpha/non-alpha ratios in both heterozygotes and homozygotes (average ratios were 1.13 and 1.56, respectively). The unbalanced biosynthetic ratios with microcytosis and hypochromia in Hb E carriers represented a beta-thalassemia phenotype, which could be a result of reduced synthesis of beta E-globin mRNA, as suggested by recent hybridization studies.
D000328:Adult; D000747:Anemia, Hypochromic / Q000097:blood / Q000235:genetics; D002648:Child; D002675:Child, Preschool; D002851:Chromatography, High Pressure Liquid; D005260:Female; D006446:Hemoglobin E / Q000032:analysis / Q000235:genetics*; D006447:Hemoglobin H / Q000032:analysis / Q000235:genetics; D006453:Hemoglobinopathies / Q000097:blood / Q000453:epidemiology / Q000235:genetics*; D006455:Hemoglobins, Abnormal / Q000235:genetics*; D006579:Heterozygote; D006720:Homozygote; D006801:Humans; D007812:Laos / Q000208:ethnology; D008297:Male; D010375:Pedigree; D011863:Radioimmunoassay; D013789:Thalassemia / Q000097:blood / Q000453:epidemiology / Q000235:genetics*; D014744:Vietnam / Q000208:ethnology
D006455:Hemoglobins, Abnormal; D006446:Hemoglobin E; D006447:Hemoglobin H