E79.82
BillableHereditary xanthinuria
HCC Category Mapping
V24HCC 23 — Other Significant Endocrine and Metabolic Disorders
0.230ESRDHCC 23 — Other Significant Endocrine and Metabolic Disorders
0.000RxHCCHCC 43 — Other Significant Endocrine and Metabolic Disorders
0.000What This Code Means
A rare inherited metabolic disorder causing excessive xanthine in urine and potentially kidney stones and muscle weakness.
Coding Tips
- •Document presence of kidney stones or muscle symptoms separately
- •Distinguish between hereditary xanthinuria and secondary xanthinuria
Clinical Significance
Hereditary xanthinuria is a rare autosomal recessive disorder caused by xanthine dehydrogenase/oxidase deficiency, resulting in inability to convert xanthine and hypoxanthine to uric acid. It presents with very low serum uric acid levels, xanthine kidney stones, and occasionally xanthine deposits in muscles, representing one of few conditions causing hypouricemia.
Documentation Requirements
- ✓Provider diagnosis of hereditary xanthinuria
- ✓Very low or absent serum uric acid levels
- ✓Elevated urine or plasma xanthine levels
- ✓History of xanthine kidney stones or urolithiasis
- ✓Genetic testing or enzyme assay confirming xanthine oxidase deficiency if available
- ✓Type classification if known: Type I (isolated XDH deficiency) or Type II (combined XDH and aldehyde oxidase deficiency)
Commonly Confused Codes
E79.0 — Hyperuricemia without gout: OPPOSITE condition — elevated uric acid, not lowE79.89 — Other disorders of purine and pyrimidine metabolism: broader purine disorder categoryN20.0 — Calculus of kidney: xanthine stones require the metabolic code in addition to the stone codeE79.9 — Disorder of purine and pyrimidine metabolism, unspecified: avoid when xanthinuria is specifically diagnosed