Question

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 dementia. the disease often manifests itself later in life, and usually victims die within 15 years of diagnosis. In some rural Michigan populations, the frequency of people diagnosed with the disorder is unusually high, about 0.05%. Genetic work shows that the wildtype allele (+) mutates into H at a rate of 9.56E-7 mutations per gamete.

1. a)Using the data estimate how many children out of 10,000,000 births to parents without the disorder will have Huntington Chorea.

b) if the population is at mutation-selection equilibrium, estimate the relative fitness of individuals possessing this genetic disorder. Assume that homozygotes for the H allele are non-existent because the H allele is super rare, and all individuals with Huntington Chorea are heterozygotes (H+).

Answer 1