Which of the Following is True of Phenylketonuria (PKU)

Question

Which of the following is true of phenylketonuria (PKU)?
A) It can result in shortened limbs.
B) It is caused by the substitution of one allele for another at a single locus.
C) It is not a genetically inherited disease.
D) It is an adaptation to malaria.

Accepted Answer

PKU is caused by a mutation in a single gene that leads to a deficiency in the enzyme phenylalanine hydroxylase. This results in the buildup of phenylalanine, which can cause intellectual disability, seizures, and other complications. PKU is inherited in an autosomal recessive manner, meaning an individual must inherit two copies of the mutated gene (one from each parent) to develop the disorder. There is no known benefit or adaptation to malaria associated with PKU. Shortened limbs are not a characteristic of PKU.