E72.51
BillableNon-ketotic hyperglycinemia
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 genetic disorder where the body cannot properly break down the amino acid glycine, leading to abnormally high glycine levels in the blood and urine without ketones present.
Coding Tips
- •This is a specific metabolic disorder requiring documentation of the non-ketotic presentation to distinguish from other glycine metabolism disorders
- •Verify genetic testing results are documented to support diagnosis, as this is an inherited condition
Clinical Significance
Non-ketotic hyperglycinemia is a severe inborn error of glycine metabolism caused by defects in the glycine cleavage system, leading to toxic accumulation of glycine in the brain and cerebrospinal fluid. This condition causes intractable seizures, profound intellectual disability, and high early mortality. Accurate coding is essential as these patients require intensive, lifelong multidisciplinary care.
Documentation Requirements
- ✓Confirmed diagnosis of non-ketotic hyperglycinemia (glycine encephalopathy)
- ✓Elevated cerebrospinal fluid-to-plasma glycine ratio confirming the diagnosis
- ✓Genetic testing results identifying mutations in glycine cleavage system genes (GLDC, AMT, GCSH)
- ✓Documentation of clinical form: neonatal, infantile, or late-onset/attenuated
- ✓Current treatment including sodium benzoate, dextromethorphan, or anti-seizure medications
Commonly Confused Codes
E72.50 — Disorder of glycine metabolism, unspecified: use only when the specific type is not documentedE72.59 — Other disorders of glycine metabolism: for glycine disorders other than NKHE72.52 — Trimethylaminuria: different metabolic pathway, not a glycine cleavage defectG40.89 — Other seizures: seizures are a manifestation of NKH, not the primary diagnosis
Code Hierarchy
└E72Other disorders of amino-acid metabolism└E72.5Disorders of glycine metabolism└E72.51Non-ketotic hyperglycinemia
└E72.51Non-ketotic hyperglycinemia