Haptoglobin types in Brazilian Negroes

Summary 1. Haptoglobin types of 381 Negroes and 110 Whites from the city of Pôrto Alegre, Brazil, are reported. 2. The incidence of gene Hp 1 increases as the number of genes for darker pigmentation and other negroid features increases in the subsamples. Thus, Hp 1 = 0·457 in Light Mulattoes, 0·555 in Dark Mulattoes and 0·642 in Negroes. 3. The proportion of non‐Negro ancestry in the negroid population of Pôrto Alegre is estimated as being 54·5% and the average gene flow per generation to be m = 0·064. 4. No differences in haptoglobin frequencies according to age were detected but there is a significant excess of 2­1 and a lack of 2­2 individuals among those undergoing health treatment as compared with healthy persons. Our thanks are due to the Director of the ‘Instituto de Pesquisas Biológicas’ of the State Department of Health for allowing us to use the Institute's facilities for the collection of blood. Mr Arno R. Schwantes helped in the checking of a series of plasma samples and Mr Girley V. Simoes in the collection and analysis of the data. The work has been supported in part by Rockefeller Foundation grants, by PHS research grant RG­8238 from the Division of General Medical Sciences, Public Health Service, U.S.A. and by research grant T.C. 2668 from the National Research Council of Brazil.