Question

Hardy-Weinberg equilibrium:

In a certain population in the US, the frequency of CCR5-Δ32 homozygous individuals is 1%. Assuming genetic equilibrium, what is the frequency of heterozygotes in this population?

In a certain population in the US, the frequency of CCR5-Δ32 homozygous individuals is 0.0016. Assuming Hardy-Weinberg equilibrium, what is the frequency of the normal allele, CCR5-1?

Answer 1

a) given,

frequency of CCR5-32 homozygous individual, who has resistant allele against HIV ,q^2 = 0.01 or 1% or (1/100)

according to hardy Weinberg equilibrium,  

^2 = 0.01

q = root of 0.01

q = 0.1

by HWE, p + q = 1,

hence , p, freqency of normal allele = 1 - q = 1-0.1 = 0.9

frequency of heterozygous individual = 2 p q = 2 x 0.9 x 0.1 = 0.18 or 18 %

b) q^2, frequency of genotype which is homozygous for CCR5-32 = 0.0016

q = root of 0.0016

q = 0.04

by HWE, p + q = 1

p, frequency of normal allele = 1 - q = 1 - 0.4 = 0.6

frequency of individuals with normal genotype , p^2 = 0.6 x 0.6 = 0.36