alpha-thalassemia in Bantu population from Congo-Brazzaville: its interaction with sickle cell anemia.
Deletional alpha(+)-thalassemia (-alpha(3.7)) was investigated in four groups of unrelated individuals from the Bantu population (newborns, normal adults, sickle cells trait carriers, sickle cell anemia patients) of Brazzaville, 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 and nonsickler subjects. The frequency of the (-alpha(3.7)) chromosome in sickle cell anemia patients (SS patients) did not change when age was stratified. The hematological characteristics of SS patients with (-alpha/alphaalpha, -alpha/-alpha) and without (alphaalpha/alphaalpha) alpha(+)-thalassemia were similar to those reported in Jamaican and US sickle cell anemia patients. alpha(+)-Thalassemia had an effect on the percentage of hemoglobin S in sickle cell trait carriers. Thus, the high frequency of alpha(+)-thalassemia in the Congolese population presumably results from this disorder having a selective advantage favoring survival. However, the frequency of alpha(+)-thalassemia was not affected by age. Although in this selective tropical environment, alpha(+)-thalassemia as elsewhere markedly affects the hematological characteristics of sickle cell anemia patients, however our data provide no evidence that alpha(+)-thalassemia increases survival of SS patients.
Mouélé
R
R
Unité de Recherches en Génétique Moléculaire et Hématologie, INSERM U474, Hôpital Henri Mondor, AP-HP, Créteil, France.
Pambou
O
O
Feingold
J
J
Galactéros
F
F
D000293:Adolescent; D000328:Adult; D000349:Africa; D000755:Anemia, Sickle Cell / Q000150:complications* / Q000235:genetics; D002648:Child; D002675:Child, Preschool; D005787:Gene Frequency; D006801:Humans; D007223:Infant; D017384:Sequence Deletion; D017085:alpha-Thalassemia / Q000150:complications* / Q000235:genetics