Phenylalanine and Tyrosine, Quantitative (Plasma)
This test is used to monitor the treatment of patients with phenylketonuria (PKU), an autosomal recessive disorder of phenylalanine metabolism. With rare exceptions, these patients are identified presymptomatically by newborn screening. For new patients presenting with symptoms suggestive of untreated PKU (developmental delay or mental retardation, microcephaly), please order quantitative amino acids (plasma) and urine organic acids,
