Answer:
The correct answer would be "100 percent chances".
Phenylketonuria (PKU) is a genetic disorder which causes build up of amino acid phenylalanine in the body.
It is a recessive disorder, that is, two copies of mutant alleles should be present in a person in order to produce a phenotype.
So, if both mother and father have this disease then, both should have homozygous recessive genotype, that is, pp.
Thus, only one type of gamete would be produced by both the parents.
The cross would result in the production of offspring with homozygous recessive genotype, that is, a diseased phenotype.
Thus, 100 percent chances are there to have the disease.
