ICD-10 Code E79.1 – Lesch-Nyhan Syndrome (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code E79.1 – Lesch-Nyhan syndrome
What it is
E79.1 identifies Lesch-Nyhan syndrome, a rare inherited disorder of purine metabolism. It is associated with uric acid overproduction and severe neurologic and behavioral features.
Clinical signs
Typical findings include developmental delay, dystonia, choreoathetosis, and self-injurious behavior. Hyperuricemia, gout, or kidney stones may also be documented; clinical features vary, so refer to documentation.
When to use this code
Use E79.1 when the provider documents Lesch-Nyhan syndrome or confirms the diagnosis in a patient with the characteristic metabolic and neurologic disorder. Code it when the record clearly links the condition to the patient’s inherited purine metabolism defect. If the note only mentions elevated uric acid without the syndrome, do not assume this code.
Do not use for
Do not use E79.1 for isolated hyperuricemia, gout, or kidney stones without documented Lesch-Nyhan syndrome. Check documentation if the record is unclear or if the diagnosis is only suspected.
Coding tip
Verify that the provider names Lesch-Nyhan syndrome explicitly before assigning E79.1.