CPT® Code 84030

Phenylalanine is an essential amino acid that is naturally present in many protein-containing foods. The CPT® Code 84030 refers to a blood test specifically designed to measure the levels of phenylalanine in the bloodstream. This test is crucial for identifying individuals with phenylketonuria (PKU), a genetic disorder caused by a deficiency in the hepatic enzyme phenylalanine hydroxylase (PAH). When this enzyme is nonfunctional due to a genetic mutation, the body is unable to convert phenylalanine into another amino acid called tyrosine. As a result, phenylalanine accumulates in the blood, which can lead to severe neurological damage if not detected and managed early. The blood test for phenylalanine is typically performed as part of a Newborn Screening Panel, ensuring that infants are screened shortly after birth for this potentially harmful condition. Various testing methods may be employed to measure phenylalanine levels, including the bacterial inhibition assay known as the Guthrie test, as well as fluorometric or photometric immunoassays. Additionally, tandem mass spectrometry may be utilized to measure amino acids, providing accurate and reliable results for the diagnosis of PKU.