A Study of the Su Alleles in Northeastern Brazil*

作者：Newton E. Morton, M. P. Mi, N. Yasuda · 发表于：Vox Sanguinis · 年份：1966 · DOI：10.1111/j.1423-0410.1966.tb04222.x · 被引用次数：11 · 研究领域：Genetic and Clinical Aspects of Sex Determination and Chromosomal Abnormalities、T-cell and B-cell Immunology、Blood groups and transfusion

Summary In a northeastern Brazilian population with 30% Negro admixture, the frequencies of S‐s‐ alleles at the MNS locus are N* = 0.0189, M* = 0.0138, where the asterisk signifies that the reaction with anti‐U is not specified. Of 8 independent homozygotes, 4 reacted with anti‐U. This is greater than, but not significantly different from the proportions of U + and U‐ reported in American Negroes by Allen et al. (1963), and the pooled estimate is that 16% of N* genes are NU and 5% of M* genes are MU. After deleting parentage exclusions by other systems, the frequency of parentage errors among inferred N* and M* heterozygotes is shown to be 0.048±0.038, and the overall frequency of undetected parentage errors is 0.010±0.006. Neither estimate is significantly different from zero, nor is the racial phenotype of inferred heterozygotes significantly different from its expectation on the hypothesis that (almost) all inferred heterozygotes in this population are genuine, and not the result of extramarital parentage. No recombination was observed between MN and inferred S‐s‐ alleles in 180 gametes tested. As an explanation of N* and M* “alleles”, the data clearly exclude an unlinked modifier (P<10‐44) or a linked modifier more than 1.3 crossover units from the MN locus. Following the conventional definition of a locus in human genetics, N* and M* may be accepted as alleles at the MNS locus. Résumé Dans les populations du Nord‐Est brésilien comportant 30% de personnes de race noire, l...