Phenylketonuria (pku) is a disease caused by a recessive mutation. pku is extremely common in ireland, affecting approximately 1 in 4500 live births. assuming that the population is in hardy-weinberg equilibrium, what is the frequency of homozygous wild-type individuals (i. e., people without the recessive mutation)? phenylketonuria (pku) is a disease caused by a recessive mutation. pku is extremely common in ireland, affecting approximately 1 in 4500 live births. assuming that the population is in hardy-weinberg equilibrium, what is the frequency of homozygous wild-type individuals (i. e., people without the recessive mutation)? 98.5% 2.96% 97% 1.5% 0.022%