Polymorphic admixture typing in human ethnic populations

Am J Hum Genet. 1994 Oct;55(4):788-808.


A panel of 257 RFLP loci was selected on the basis of high heterozygosity in Caucasian DNA surveys and equivalent spacing throughout the human genome. Probes from each locus were used in a Southern blot survey of allele frequency distribution for four human ethnic groups: Caucasian, African American, Asian (Chinese), and American Indian (Cheyenne). Nearly all RFLP loci were polymorphic in each group, albeit with a broad range of differing allele frequencies (delta). The distribution of frequency differences (delta values) was used for three purposes: (1) to provide estimates for genetic distance (differentiation) among these ethnic groups, (2) to revisit with a large data set the proportion of human genetic variation attributable to differentiation within ethnic groups, and (3) to identify loci with high delta values between recently admixed populations of use in mapping by admixture linkage disequilibrium (MALD). Although most markers display significant allele frequency differences between ethnic groups, the overall genetic distances between ethnic groups were small (.066-.098), and < 10% of the measured overall molecular genetic diversity in these human samples can be attributed to "racial" differentiation. The median delta values for pairwise comparisons between groups fell between .15 and .20, permitting identification of highly informative RFLP loci for MALD disease association studies.

Publication types

  • Comparative Study

MeSH terms

  • African Continental Ancestry Group / genetics
  • Alleles
  • Asian Continental Ancestry Group / genetics
  • Biometry
  • Blotting, Southern
  • Cells, Cultured
  • China / ethnology
  • Chromosome Mapping*
  • DNA / blood
  • DNA / genetics
  • DNA Probes
  • Ethnic Groups / genetics*
  • European Continental Ancestry Group / genetics*
  • Gene Frequency*
  • Genetic Markers
  • Genetic Variation*
  • Humans
  • Indians, North American / genetics
  • Polymorphism, Restriction Fragment Length*
  • United States


  • DNA Probes
  • Genetic Markers
  • DNA