E77.0
BillableDefects in post-translational modification of lysosomal enzymes
HCC Category Mapping
V24HCC 23 — Other Significant Endocrine and Metabolic Disorders
0.230ESRDHCC 23 — Other Significant Endocrine and Metabolic Disorders
0.000RxHCCHCC 41 — Lysosomal Storage Disorders
0.000What This Code Means
A rare genetic disorder affecting how the body modifies and processes lysosomal enzymes, which are proteins that break down waste materials in cells.
Coding Tips
- •This code requires documentation of the specific enzyme defect when available
- •Often associated with lysosomal storage diseases; review clinical findings for more specific diagnosis
Clinical Significance
Defects in post-translational modification of lysosomal enzymes includes mucolipidosis II (I-cell disease) and mucolipidosis III (pseudo-Hurler polydystrophy), where lysosomal enzymes are not properly tagged for delivery to lysosomes. These are severe conditions with clinical features overlapping MPS but with distinct pathophysiology, requiring differentiation for appropriate genetic counseling and management.
Documentation Requirements
- ✓Specific disorder documented: mucolipidosis II (I-cell disease) or mucolipidosis III (pseudo-Hurler polydystrophy)
- ✓Confirmatory testing: elevated serum lysosomal enzyme levels, decreased intracellular enzyme activity, or GNPTAB/GNPTG gene mutations
- ✓Clinical manifestations: skeletal abnormalities, coarse features, developmental delay, cardiac involvement
- ✓Differentiation from MPS documented (different enzyme trafficking defect mechanism)
- ✓Treatment plan and current disease status
Commonly Confused Codes
E76.01 — Hurler syndrome: similar clinical features but different pathophysiology (direct enzyme deficiency vs. enzyme trafficking defect)E77.1 — Defects in glycoprotein degradation: different step in glycoprotein processingE76.3 — Mucopolysaccharidosis, unspecified: mucolipidoses are NOT mucopolysaccharidoses despite overlapping featuresE77.8 — Other disorders of glycoprotein metabolism: for glycoprotein disorders not classified in E77.0 or E77.1
Code Hierarchy
└E77Disorders of glycoprotein metabolism└E77.0Defects in post-translational modification of lysosomal enzymes
└E77.0Defects in post-translational modification of lysosomal enzymes