Hello I need some help with an Evolutionary Biology problem dealing with a Delet

Question

Hello I need some help with an Evolutionary Biology problem dealing with a Deleterious Dominant Mutation. I have posted the whole problem but honestly I would just be happy with how to get started and how to understand the problem. I missed the lecture when this topic was discussed so I am very lost. Please help me.

(15 points total) Huntington Chorea is a serious genetic disorder caused by a rare dominant allele (H) at an autosomal locus on chromosome 4. Individuals bearing an H allele produce a damaging protein that accumulates within the brain, leading to progressive loss of motor control and often to dementia. Usually, Huntington Chorea victims die within 15 years after their neurological symptoms are diagnosed. In some rural Michigan populations, the frequency of people diagnosed with the disorder is unusually high, about 0.05%. On average in these populations, 1 child out of every 273,000 births to parents without the disorder will have Huntington

Explanation / Answer

Based on the given data, the newborns have HH and Hh alleles will die and only people with “hh” (homozygous recessive individuals) will live. The given homozygous dominant and homozygous recessive individuals frequency is 0.05% or 5*10-2. The occurrence of mutation is 1/273,000 births = 3.6*10-6 or 0.000003663 or 0.00036%.

The selection coefficient (S) for HH and Hh is 0.05 and the S for hh is 0.95

For low range selection (HH and Hh):

O = µ/s

5*10-2 = µ/ 0.05

µ = 0.05 (5*10-2) = 2.5*10-3

For High range selection (hh):

O = µ/s

5*10-2 = µ/ 0.95

µ = 0.95 (5*10-2) = 4.7*10-2

Thus, the mutation rate is 2.5*10-3.

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