Lewis Phenotypes of American Caucasians, American Negroes and Their Children

. Lewis antisera produced in goats was used to test the red blood cells of 1,818 unrelated American adults and 758 unrelated children. All lived in northeastern states of the USA. Among 935 Caucasian adults, the frequency of Le(a‐b‐), Le(a+b‐), and Le(a‐b+), red cell phenotypes was 9.7, 20.1 and 70.2%, respectively. Among 883 Negro adults, the frequency of these phenotypes was 28.5, 19.6 and 51.9%, respectively. Among 469 infants aged 1–24 months, the red cell phenotype Le(a+b+) was found in 37.4% of 265 Caucasians and 13.2% of 204 Negroes.