Alpha Thalassaemia in Adults with Sickle‐Cell Trait

Publisher Website
Google Scholar
Abstract
Summary. Mild forms of α thalassaemia are difficult to detect in adults. Since α thalassaemia existing with structural defects of the β chain of haemoglobin may lead to decreased levels of the abnormal haemoglobin, we examined individuals having sickle‐cell trait for the possible coexistence of α thalassaemia. Patients with sickle‐cell trait having haemoglobin‐S (Hb‐S) levels less than commonly expected were compared to two control groups—one with sickle‐cell trait and the usual levels of Hb S and one with normal haemoglobin. Twenty‐one patients with sickle‐cell trait having Hb‐S concentrations below 35% had 65.8% Hb A, 31.8% Hb S, and a mean corpuscular volume of 81.6 fl. Studies of the relative rates of α‐, βs‐ and βA‐chain synthesis in 14 of these individuals showed a mean α:β ratio of 0.76. In patients with normal haemoglobin as well as in sickle‐cell trait with Hb‐S levels above 35%, this ratio was unity. These findings are consistent with the presence of α thalassaemia in patients with sickle‐cell trait who have lower than usual levels of Hb S and micro‐cytosis.