Distribution of HbS Gene and Variability of the Index of the Opportunity for Natural Selection in a Caste Population of Western Orissa, India.

Abstract

Pattern of distribution of HbS gene among the people in a caste population of India was studied through the estimation of its frequency in different isolates, age groups and generations. Crow's index of the opportunity for natural selection among the live births in completed families, based on sickle cell genotype of parents, was estimated to check the suspected superior fertility potentials of AS over AA women. It is observed that genotype frequencies are in equilibrium in each of the three isolates of the population and there exists no significant difference between isolates. Among the adults similarly, nonsignificant differences in frequency between two successive age groups and between generations are observed. Opportunity for natural selection is highest among families in which one or both of the parents are AS. Nonsignificant but lightly higher mean fertility is observed from AA × AS than AA × AA atings.