7) A rare dominant genetic disorder has an allele frequency of0.00002. It is estimated to reduce the fitness of affectedindividuals by 50%. Under mutation-selection balance affecting adominant, the mutation rate is predicted to be about half theequilibrium allele frequency, or 0.00001. We’ll assume this is thecase here.
A) What is the frequency of affected individuals? (You couldcalculate an exact answer, but try getting a simple approximationusing the fact that homozygotes for the mutant allele would beexceptionally rare, and the frequency of the wild-type allele isvery close to 1)
B) Suppose a medical treatment for the disorder was developedthat, although extremely expensive, allowed affected individuals tolive normal lives. If everyone who needed it received thetreatment, there would no longer be any selection against themutant allele. What would be the allele frequency after 10generations in this case? (You need your calculator for an exactanswer, but you are encouraged to try to come up with a goodapproximation first, using your intuition and pencil and paper.Then check it with a calculator).
C) What would be the predicted frequency of affected individualsafter 10 generations? How would this compare to the originalfrequency?
D) In your opinion, would the answer to (C) make you pausebefore recommending that the treatment be made available to anyonewho needs it, at government expense? Why or why not?
(The answer currently posted for this question is notcorrect)
