[Viability of beta-thalassemia hetero- and homozygotes in several populations of Central Asia].

Viability of hetero- and homozygotes for beta-thalassemia was studied in two isolated populations born after 1950 in conditions of malaria absence. Pregnancy outcomes and probability to get 16 years old were compared in marriages, in which one or both parents were heterozygous for beta-thalassemia, and in marriages, with both parents being normal. The ratio of children with normal genotype and children heterozygous for beta-thalassemia in families, where one parent was heterozygous for beta-thalassemia. Preliminary conclusions are made on the basis of the data obtained. Viability of children in families where one parent is heterozygous for beta-thalassemia is found to decrease in the absence of selective factors (malaria) as compared with normal children. The highest viability decrease was observed in the progeny of those families where both parents were heterozygous beta-thalassemia. Elimination mainly takes place within the first year of life.