2026 ICD-10-CM Diagnosis Code E79.1Lesch-Nyhan syndrome

ICD-10-CM Codes›E00–E89›E70-E88›E79

ICD-10-CM E79.1
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

E79.1 is a billable ICD-10-CM diagnosis code for Lesch-Nyhan syndrome. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). Coders also document this condition as blood urate above reference range. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified and unspecified nutritional and metabolic disorders.

Code Identity

ICD-10-CM Code
E79.1
Billable Status
Yes — Valid for Submission
Code Describes
Lesch-Nyhan syndrome
Short Description
Lesch-Nyhan syndrome
Same as the full description in the CMS dataset.
Parent Code
E79
Disorders of purine and pyrimidine metabolism

Code Classification

ChapterE00–E89Endocrine, nutritional and metabolic diseases
SectionE70-E88Metabolic disorders
CategoryE79Disorders of purine and pyrimidine metabolism
This CodeE79.1Lesch-Nyhan syndrome

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Blood urate above reference range
  • Blood urate outside reference range
  • Chorea due to Lesch-Nyhan syndrome
  • Chorea due to metabolic disorder
  • Deficiency of hypoxanthine phosphoribosyltransferase
  • Dystonia due to Lesch Nyhan syndrome
  • Hyperuricemia
  • Lesch-Nyhan syndrome
  • Partial hypoxanthine-guanine phosphoribosyltransferase deficiency

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • HGPRT deficiency

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Arthropathy
      • gouty
        • in (due to)
          • Lesch-Nyhan syndrome
    • Deficiency, deficient
      • hypoxanthine- (guanine)-phosphoribosyltransferase (HG- PRT) (total H-PRT)
    • Lesch-Nyhan syndrome

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR END016
Other specified and unspecified nutritional and metabolic disorders
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Hyperuricemia

    excessive uric acid or urate in blood as defined by its solubility in plasma at 37 degrees c; greater than 0.42mmol per liter (7.0mg/dl) in men or 0.36mmol per liter (6.0mg/dl) in women. this condition is caused by overproduction of uric acid or impaired renal clearance. hyperuricemia can be acquired, drug-induced or genetically determined (lesch-nyhan syndrome). it is associated with hypertension and gout.

  • Lesch-Nyhan Syndrome

    an inherited disorder transmitted as a sex-linked trait and caused by a deficiency of an enzyme of purine metabolism; hypoxanthine phosphoribosyltransferase. affected individuals are normal in the first year of life and then develop psychomotor retardation, extrapyramidal movement disorders, progressive spasticity, and seizures. self-destructive behaviors such as biting of fingers and lips are seen frequently. intellectual impairment may also occur but is typically not severe. elevation of uric acid in the serum leads to the development of renal calculi and gouty arthritis. (menkes, textbook of child neurology, 5th ed, pp127)

  • Hypoxanthine Phosphoribosyltransferase

    an enzyme that catalyzes the conversion of 5-phosphoribosyl-1-pyrophosphate and hypoxanthine, guanine, or mercaptopurine to the corresponding 5'-mononucleotides and pyrophosphate. the enzyme is important in purine biosynthesis as well as central nervous system functions. complete lack of enzyme activity is associated with the lesch-nyhan syndrome, while partial deficiency results in overproduction of uric acid. ec 2.4.2.8.

Patient EducationClinical

Amino Acid Metabolism Disorders

Metabolism is the process your body uses to make energy from the food you eat. Food is made up of proteins, carbohydrates, and fats. Your digestive system breaks the food parts down into sugars and acids, your body's fuel. Your body can use this fuel right away, or it can store the energy in your body.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert E79.1 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
277.2 Purine/pyrimid dis NEC
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About E79.1Overview

Is E79.1 (Disorders of purine and pyrimidine metabolism) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report Lesch-Nyhan syndrome on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What is the ICD-9 equivalent of E79.1?

Under the General Equivalence Mappings, Lesch-Nyhan syndrome converts to ICD-9-CM 277.2 (purine/pyrimid dis NEC). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.