alpha-thalassemia in Bantu population from Congo-Brazzaville: Its interaction with sickle cell anemia

Deletional alpha(+)-thalassemia (-alpha(3.7)) was investigated in four grou ps of unrelated individuals from the Bantu population (newborns, normal adu lts, sickle cells trait carriers, sickle cell anemia patients) of Brazzavil le, Congo, The frequency of the (-alpha 3.7) chromosome was similar between newborns (f = 0.40) and adult subjects (f = 0.36), and between sicklers an d nonsickler subjects. The frequency of the (-alpha(3.7)) chromosome in sic kle cell anemia patients (SS patients) did not change when age was stratifi ed. The hematological characteristics of SS patients with (-alpha/alpha alp ha, -alpha/-alpha) and without (alpha alpha/alpha alpha) alpha(+)-thalassem ia were similar to those reported in Jamaican and US sickle cell anemia pat ients, alpha(+)-Thalassemia had an effect on the percentage of hemoglobin S in sickle cell trait carriers. Thus, the high frequency of alpha(+)-thalas semia in the Congolese population presumably results from this disorder hav ing a selective advantage favoring survival, However, the frequency of alph a(+)-thalassemia was not affected by age, Although in this selective tropic al environment, alpha(+)-thalassemia as elsewhere markedly affects the hema tological characteristics of sickle cell anemia patients, however our data provide no evidence that alpha(+)-thalassemia increases survival of SS pati ents, Copyright (C) 1999 S. Karger AG, Basel.