Incidence of Down's syndrome in American Negroes

The incidence of births of children with Down's syndrome identified in infants in Memphis-Shelby County, Tennessee, is given by race from 1955 to 1966. There were 100 infants with Down's syndrome in the Caucasian population with a rate of 0.95 per 1,000 live births and 92 infants in the Negro population with a rate of 1.02 per 1,000 live births. Annual incidence rates show evidence of periodic aggregations of Down's syndrome which are similar in the two races. This suggests that there is no difference between rates of Down's syndrome in Caucasians and Negroes in the population observed.