Other disorders of aromatic amino-acid metabolism

This code signifies rare, inherited metabolic disorders affecting the breakdown or synthesis of aromatic amino acids (e.g., phenylalanine, tyrosine, tryptophan) that are not specifically classified elsewhere. These conditions result from enzyme deficiencies, leading to the accumulation of toxic metabolites or deficiencies of essential compounds.

Apply this code for documented diagnoses of atypical or unspecified disorders of aromatic amino acid metabolism, such as hyperphenylalaninemia not due to classical PKU, or other unclassified defects in tyrosine or tryptophan metabolism. Supporting documentation should clearly state the specific metabolic pathway affected and rule out more specific diagnoses.

• Ensure documentation specifies "other" or "unspecified" aromatic amino acid metabolism disorder when a more precise code is unavailable.
• Do not use this code for classical phenylketonuria (PKU) or tyrosinemia, which have their own specific codes.
• Consider sequencing this code as a primary diagnosis if it is the main reason for the encounter, or as a secondary diagnosis if it is a comorbidity.