E79.1 Lesch-Nyhan syndrome

Billable ICD-10-CM code, FY2026. Acts as a Complication or Comorbidity (CC) as a secondary diagnosis.

Applicable to

• HGPRT deficiency

Applies from E79 Disorders of purine and pyrimidine metabolism

Excludes1 (never code together)

• Ataxia-telangiectasia (Q87.19)
• Bloom's syndrome (Q82.8)
• Cockayne's syndrome (Q87.19)
• calculus of kidney (N20.0)
• combined immunodeficiency disorders (D81.-)
• Fanconi's anemia (D61.09)
• gout (M1A.-, M10.-)
• orotaciduric anemia (D53.0)
• progeria (E34.8)
• Werner's syndrome (E34.8)
• xeroderma pigmentosum (Q82.1)

Risk adjustment (HCC)

• CMS-HCC V28: HCC 50 — Amyloidosis, Porphyria, and Other Specified Metabolic Disorders
• CMS-HCC V22: HCC 23 — Other Significant Endocrine and Metabolic Disorders
• RxHCC V08: HCC 43 — Pituitary, Adrenal Gland, and Other Endocrine and Metabolic Disorders
• ESRD V24: HCC 23

MS-DRG index

Defines the logic of DRG(s) 642 in MDC 10.

Approximate ICD-9-CM (GEMs)

• 277.2 Other disorders of purine and pyrimidine metabolism (approximate)

Code annotations containing back-references to E79.1

Back-references to E79.1

• Type 1 Excludes: D53.0 Protein deficiency anemia ("Lesch-Nyhan syndrome (E79.1)")

Back-references to E79

• Type 1 Excludes: E72 Other disorders of amino-acid metabolism ("purine and pyrimidine metabolism (E79.-)")
• Type 2 Excludes: G11 Hereditary ataxia ("metabolic disorders (E70-E88)")
• Type 2 Excludes: G11.3 Cerebellar ataxia with defective DNA repair ("other disorders of purine and pyrimidine metabolism (E79.-)")
• Code First: G63 Polyneuropathy in diseases classified elsewhere ("metabolic diseases (E70-E88)")
• Type 2 Excludes: G71 Primary disorders of muscles ("metabolic disorders (E70-E88)")
• Code First: H42 Glaucoma in diseases classified elsewhere ("specified metabolic disorder (E70-E88)")
• Type 2 Excludes: N25.0 Renal osteodystrophy ("metabolic disorders classifiable to E70-E88")
• Type 2 Excludes: N25.81 Secondary hyperparathyroidism of renal origin ("metabolic disorders classifiable to E70-E88")
• Type 1 Excludes: P59 Neonatal jaundice from other and unspecified causes ("jaundice due to inborn errors of metabolism (E70-E88)")

Diagnosis Index entries for E79.1

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

Nearby codes

• E79 Disorders of purine and pyrimidine metabolism
• E79.0 Hyperuricemia without signs of inflammatory arthritis and tophaceous disease
• E79.1 Lesch-Nyhan syndrome (this code)
• E79.2 Myoadenylate deaminase deficiency
• E79.8 Other disorders of purine and pyrimidine metabolism
• E79.81 Aicardi-Goutieres syndrome
• E79.82 Hereditary xanthinuria
• E79.89 Other specified disorders of purine and pyrimidine metabolism