Disorders of histidine metabolism, unspecified

This code signifies a metabolic disorder affecting the breakdown of histidine, an essential amino acid, when the specific type of disorder is not identified. These conditions typically involve enzyme deficiencies leading to an accumulation of histidine or its metabolites in the body, potentially impacting neurological function.

Use this code when documentation indicates a confirmed or suspected disorder of histidine metabolism, but the specific enzyme deficiency (e.g., histidinemia, histidinuria) is not specified. This code is appropriate when laboratory findings suggest an issue with histidine metabolism, but further diagnostic workup is pending or inconclusive.

• Avoid using this code if a more specific disorder of histidine metabolism (e.g., histidinemia) is documented; instead, use the appropriate subcategory code.
• Ensure documentation supports an unspecified diagnosis; if the provider suspects a specific type, query for clarification.
• Consider sequencing this code as a primary diagnosis when it is the reason for the encounter, or as a secondary diagnosis if it's a co-morbidity.