One of the First Medical Tests a Newborn Receives Determines

Multiple Choice

One of the first medical tests a newborn receives determines if the child has phenylketonuria (PKU) . PKU is the result of a mutation in a single gene that causes mental retardation and a host of other phenotypes (light hair and skin color, eczema, and a "mousy" smell) . By detecting PKU early, doctors are able to reduce the effect of this condition with a modified diet. PKU is an example of

A) epistasis.
B) a polygenic trait.
C) pleiotrophy.
D) codominance.