Phenylketonuria (PKU) is a recessive genetic disorder caused…
Phenylketonuria (PKU) is a recessive genetic disorder caused by a deficiency of phenylalanine hydroxylase, the enzyme that converts phenylalanine to tyrosine. Untreated PKU is characterized by a build-up of phenylalanine and its metabolites, in the blood and eventually brain, which can lead to brain damage. Nutritional management of PKU involves a low protein (and therefore low phenylalanine) diet, and supplementation with a phenylalanine-free protein supplement. However, phenylalanine can also accumulate in the blood (and therefore brain) when someone with PKU becomes sick and/or has a poor appetite. Why might illness and/or poor appetite in a person with PKU cause the accumulation of phenylalanine in the blood/brain? (hint: consider your response to question #10 above) (3-6 sentences)