Individuals that express the disease sickle cell anemia are

Individuals that express the disease sickle cell anemia are homozygous for a recessive allele for a hemoglobin gene. The frequency of individuals expressing the disease in a particular population is 0.0025.

If we assume that the population is at HWE, what is the frequency of the recessive sickle cell allele?

If the population is at HWE, what is the expected frequency of carriers of the disease (heterozygotes)?

If mating is random, what is the probability that two carriers will mate?

*University of Washington

Solution

q² = .0025

q=.0025=0.05

(p+q=1)

(q=1-0.05=0.95)

If we assume that the population is at HWE, what is the frequency of the recessive sickle cell allele?

The frequency of the recessive sickle cell allele, q=0.05

If the population is at HWE, what is the expected frequency of carriers of the disease (heterozygotes)?

Expected frequency of carriers of the disease=2pq= 2*0.05*0.95=0.095

If mating is random, what is the probability that two carriers will mate?

The probability that two carriers will mate =0.095*0.095=9.025x10^-3 or 9.025x10^-3 x100=0.9025%