Exam 22: Risk Calculation

A 40-year-old woman is concerned for the health of her child because her own father died of Huntington's disease.The consultand currently has no signs of Huntington's disease himself.If we assume the age-dependent penetrance of Huntington's disease is 20% at age 40,what is the prior probability that the child will have inherited the disease?

How is a posterior probability calculated?

A baby tests negative by newborn screening for cystic fibrosis mutations using a mutation panel that will detect 70% of mutations in this population.If there is a carrier frequency of 1/50 in this population,what is the probability that the baby is a mutation carrier?

A couple would like to have 3 children,all boys.If they do,in fact,have 3 children,what is the probability that they will all be boys?