Disorders of purine and pyrimidine metabolism (E79) ICD-10-CM
The E79 code range covers disorders of purine and pyrimidine metabolism with 9 ICD-10-CM diagnosis codes. 7 of them are billable and valid for claim submission in fiscal year 2026, and the category headers group them but cannot themselves be billed.
Type 1 Excludes
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
Codes in the E79 Range 9 codes · 7 billable
- E79 Disorders of purine and pyrimidine metabolismNon-billable
- E79.0 Hyperuricemia without signs of inflammatory arthritis and tophaceous disease
- E79.1 Lesch-Nyhan syndrome
- E79.2 Myoadenylate deaminase deficiency
- E79.8 Other disorders of purine and pyrimidine metabolismNon-billable
- E79.81 Aicardi-Goutieres syndrome
- E79.82 Hereditary xanthinuria
- E79.89 Other specified disorders of purine and pyrimidine metabolism
- E79.9 Disorder of purine and pyrimidine metabolism, unspecified
Clinical Terms in This Code Range
Definitions from the National Library of Medicine for conditions coded in the E79 range.
Dihydropyrimidine Dehydrogenase Deficiency
An autosomal recessive disorder affecting DIHYDROPYRIMIDINE DEHYDROGENASE and causing familial pyrimidinemia. It is characterized by thymine-uraciluria in homozygous deficient patients. Even a partial deficiency in the enzyme leaves individuals at risk for developing severe 5-FLUOROURACIL-associated toxicity.
DNA
A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).
DNA End-Joining Repair
The repair of DOUBLE-STRAND DNA BREAKS by rejoining the broken ends of DNA to each other directly.
DNA Repair
The removal of DNA LESIONS and/or restoration of intact DNA strands without BASE PAIR MISMATCHES, intrastrand or interstrand crosslinks, or discontinuities in the DNA sugar-phosphate backbones.
DNA Repair Enzymes
Enzymes that are involved in the reconstruction of a continuous two-stranded DNA molecule without mismatch from a molecule, which contained damaged regions.
DNA Repair-Deficiency Disorders
Disorders resulting from defective DNA REPAIR processes or the associated cellular responses to DNA DAMAGE.
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.
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.
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)
O(6)-Methylguanine-DNA Methyltransferase
An enzyme that transfers methyl groups from O(6)-methylguanine, and other methylated moieties of DNA, to a cysteine residue in itself, thus repairing alkylated DNA in a single-step reaction. EC 2.1.1.63.
Rad52 DNA Repair and Recombination Protein
A DNA-binding protein that mediates DNA REPAIR of double strand breaks, and HOMOLOGOUS RECOMBINATION.
Recombinational DNA Repair
Repair of DNA DAMAGE by exchange of DNA between matching sequences, usually between the allelic DNA (ALLELES) of sister chromatids.
About the E79 Code Range
The ICD-10 code section E79 covers disorders related to purine and pyrimidine metabolism, essential pathways for DNA and energy regulation in the body. These codes are used to classify a range of inherited and acquired metabolic conditions affecting how purines and pyrimidines are processed.
This section includes specific codes such as E79.0 for hyperuricemia without inflammatory arthritis, also known as urate nephropathy or high uric acid levels, and E79.1 for Lesch-Nyhan syndrome, a rare deficiency of hypoxanthine phosphoribosyltransferase causing neurologic and metabolic symptoms. Code E79.2 is designated for myoadenylate deaminase deficiency, also called muscle AMP deaminase deficiency. Other codes like E79.81 identify syndromes such as Aicardi-Goutieres, while E79.82 covers hereditary xanthinuria—a genetic disorder involving xanthine oxidase deficiency. The broader E79.8 and E79.89 codes address other less common or specified purine and pyrimidine metabolism disorders. Code E79.9 is reserved for unspecified cases, including gout secondary to enzyme defects. Medical coders use these specific ICD-10 codes to accurately document and classify each unique purine or pyrimidine metabolic disorder.
Questions About This Page
How many billable codes are in the E79 range?
Of the 9 codes in this range, 7 are billable and valid for claim submission from October 1, 2025 through September 30, 2026. Category header codes group them but cannot be reported on claims.
What does the E79 range classify?
The range classifies disorders of purine and pyrimidine metabolism. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.
Related References
Source: CMS FY 2026 ICD-10-CM Tabular List and order file, effective October 1, 2025 through September 30, 2026.
