Phenylketonuria or PKU is an autosomal recessive condition resulting from one of a number of mutations in the gene encoding the amino acid converting enzyme phenylalanine hydroxylase (PheOH). PheOH requires the cofactor tetrahydrobiopterin (BH4). All newborns are tested for PKU at birth. Untreated PKU will lead to permanent neurological damage.
Consider the likely biochemical reaction catalyzed by PheOH and then identify ALL of the following statements which are NOT true concerning untreated individuals testing positive for PKU.
Select ALL that apply.