What Are the Implications of Genetic Differentiation on Race and Ethnicity?
Population geneticists have shown that although the genetic variation between specific population groups is smaller than within population groups, the amount of variation in the human genome is substantial. At least 15 million genetic polymorphisms are estimated to exist in the human genome.3 Analysis of polymorphisms in the 5 racial/ethnic groups identified in the 2000 US Census show that these 45 groups aggregate genetically.4,5 The allele frequencies for single-nucleotide polymorphisms and microsatellite markers indicate a median difference of 15% to 20% between racial and ethnic groups; 10% of polymorphic markers differ by ≥40%.6,7 Although no unifying sequence defines racial groups, the variation within the human genome does appear to align along self-identified race or ethnicity.8 Thus, the frequency of alleles associated with CVD is likely to vary substantially among racial/ethnic groups.
