Determine whether the following two sets of data represent p

Determine whether the following two sets of data represent populations that are in Hardy-Weinberg equilibrium: CCR5 genotypes: 1/1, 60 percent; 1/Delta 32, 35.1 percent; Delta 32/Delta 32, 4.9 percent Sickle-cell hemoglobin: AA, 75.6 percent; AS, 24.2 percent; SS, 0.2 percent

Solution

For, populations that exist in Hardy-Weinberg (H-W) equilibrium, genotypic frequencies are such that: p² + 2pq + q² = 1, and gene frequencies are: p + q = 1

a. Given that 1/1 = 0.6; 1/^32 = 0.351; and ^32/^32 = 0.49

Gene frequency of 1 = 0.6 = 0.775; gene frequency of ^32 = 0.49 = 0.7.

Sum of gene frequencies = 0.775 + 0.7 = 1.475 (> 1.0). Similarly, genotypic frequency of 1/^32 should be 2(0.775)(0.7) = 1.085 (not 0.351!)

Hence, this population is not in H-W equilibrium.

b. Given that AA = 0.756; AS = 0.242; and SS = 0.2

gene frequency of A = 0.756 = 0.869; gene frequency of S = 0.2 = 0.447.

Sum of gene frequencies = 0.869 + 0.447 = 1.316 (> 1.0). Similarly, genotypic frequency of AS should be 2(0.869)(0.447) = 0.776 (not 0.242!)

Hence, this population is not in H-W equilibrium.