ICD-10 Code E70.49 – Other disorders of histidine metabolism (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code E70.49 – Other disorders of histidine metabolism
What it is
E70.49 identifies inherited disorders affecting histidine metabolism that do not fit a more specific ICD-10-CM code. Use it when the record documents a histidine metabolic disorder, but the exact subtype is not named.
Clinical signs
Clinical features vary; refer to documentation. These disorders may present in infancy or childhood with developmental concerns, neurologic findings, or abnormal metabolic screening results.
When to use this code
Use E70.49 when the provider documents an “other” or unspecified disorder of histidine metabolism and no more specific code is available. It may also apply when the diagnosis is confirmed by metabolic workup or specialist assessment, but the chart does not identify a distinct histidine disorder.
Do not use for
Do not use this code for a clearly documented, specific inborn error of metabolism that has its own ICD-10-CM code. If the record only says “metabolic disorder” without histidine involvement, check documentation.
Coding tip
Query the clinician for the exact histidine disorder when the diagnosis is vague, because a more specific code may be available.