Serum phenylalanine

The conversion of phenylalanine to tyrosine in the body requires the participation of phenylalanine hydroxylase. If phenylalanine hydroxylase is lacking in the body, phenylalanine metabolism disorder will occur, making phenylalanine unable to be converted into tyrosine, and phenylpyruvate is excreted from the urine, which is called phenylpyruvateuria. At this time, the patient's plasma phenylalanine increased and tyrosine decreased. Phenylketonuria (PKU) is an autosomal recessive disease.