ALPHA-THALASSEMIA IS RELATED TO PROLONGED SURVIVAL IN SICKLE-CELL-ANEMIA

  • 1 January 1983
    • journal article
    • research article
    • Vol. 62  (2) , 286-290
Abstract
The frequency of deletional .alpha.-thalassemia in black populations in the USA and Africa that harbor sickle cell anemia was determined. In normals, the frequency of the chromosome bearing a deletion of 1 of the 2 normal .alpha. gene loci, designated (-.alpha.), ranged from 0.12-0.16, and in sickle trait subjects, the frequency ranged from 0.18-0.20. By contrast, in sickle cell anemia subjects, the frequency was significantly greater and ranged from 0.22-0.33. The greater frequency in the last group was primarily a result of an increased number of subjects with .alpha.-thalassemia trait (also called homozygous .alpha.-thalassemia-2). In addition, the frequency of the (-.alpha.) chromosome was found to increase progressively with age, supporting the hypothesis that .alpha.-thalassemia is favorable to the survival of subjects with sickle cell anemia. Thus, individuals who inherit .alpha.-thalassemia and sickle cell anemia may represent a subgroup of patients with a longer life expectancy.