E70.21

HCC Category Mapping

What This Code Means

A rare inherited metabolic disorder where the body cannot properly break down the amino acid tyrosine, leading to toxic buildup in the liver, kidneys, and other organs.

Coding Tips

• •Tyrosinemia has multiple types (I, II, III); review documentation to determine if a more specific code applies
• •This code may require additional codes for complications such as liver disease or kidney dysfunction

Clinical Significance

Tyrosinemia is a group of rare inherited metabolic disorders caused by enzyme deficiencies in the tyrosine degradation pathway, leading to toxic accumulation of tyrosine and its metabolites. Type I (hepatorenal) is the most severe, causing progressive liver disease and renal tubular dysfunction. Type II causes corneal crystals and palmar keratosis, while Type III primarily affects the nervous system. Early treatment with nitisinone and dietary restriction can prevent organ damage.

Documentation Requirements

• ✓Documentation should specify the type of tyrosinemia (I, II, or III) when known, confirmed through enzyme activity testing or genetic analysis.
• ✓Include plasma tyrosine levels, succinylacetone levels (elevated in Type I), liver and renal function tests, and ophthalmologic examination results.
• ✓Current treatment with nitisinone (for Type I) and phenylalanine/tyrosine-restricted diet should be documented along with monitoring parameters.

Commonly Confused Codes