beta+ -Thalassemia intermedia. Genetic and biochemical study of a family including 3 cases.
3 cases of thalassemia intermedia have been found in the same family. The parents are not consanguineous but both come from the same town of Calabria (Italia). The mother is a heterozygote for beta-thalassemia, as well as the father whose globin chain synthesis is nevertheless balanced, thus suggesting an association with alpha-thalassemia. This hypothesis is confirmed by the fact that one of the offspring shows the typical characteristics of alpha-thalassemia heterozygosity. The 3 subjects with thalassemia intermedia are synthesizing the beta-globin chain in a proportion higher than that expected from the level of Hb A in peripheral blood. In 2 of them, the globin chain biosynthetic ratio measured in the blood reticulocytes is not significantly different from that usually observed in thalassemia major of either the beta o or beta+ type. In the third subject the globin chain synthesis is slightly less unbalanced probably because an alpha-thalassemia is also present. This suggests that factors other than a lesser imbalance in globin chain synthesis are involved in the occurrence of thalassemia intermedia. One of these factors could be a better survival of cells richer in Hb F than in Hb A, since these cells must have a lesser excess of alpha-chains.
D000293:Adolescent; D000328:Adult; D002648:Child; D005260:Female; D005319:Fetal Hemoglobin / Q000235:genetics; D006580:Genetic Carrier Screening; D006441:Hemoglobin A / Q000235:genetics; D006443:Hemoglobin A2 / Q000235:genetics; D006720:Homozygote; D006801:Humans; D008297:Male; D008875:Middle Aged; D010375:Pedigree; D013789:Thalassemia / Q000097:blood / Q000235:genetics*
D006441:Hemoglobin A; D006443:Hemoglobin A2; D005319:Fetal Hemoglobin