D89.44
BillableHereditary alpha tryptasemia
HCC Category Mapping
V24HCC 47 — Disorders of Immunity
0.472ESRDHCC 47 — Disorders of Immunity
0.000RxHCCHCC 99 — Immunodeficiencies
0.000What This Code Means
A hereditary condition where individuals have elevated levels of tryptase (an enzyme released by mast cells), predisposing them to mast cell activation and allergic reactions.
Coding Tips
- •Requires documentation of elevated baseline tryptase levels and family history
- •This is a genetic predisposition code; document any associated mast cell activation symptoms
Clinical Significance
Hereditary alpha tryptasemia is a genetic condition caused by increased copy number of the TPSAB1 gene encoding alpha-tryptase, resulting in elevated baseline serum tryptase levels. It affects approximately 5-6% of the general population and can present with mast cell activation-like symptoms including flushing, gastrointestinal dysmotility, connective tissue laxity, and dysautonomia. While often asymptomatic, symptomatic individuals may experience significant morbidity.
Documentation Requirements
- ✓Documentation should include genetic testing confirming increased TPSAB1 gene copy number, baseline elevated serum tryptase levels, and associated clinical symptoms.
- ✓Family history of elevated tryptase or similar symptoms supports the diagnosis.
- ✓The provider should document whether the patient is symptomatic or the finding is incidental, and note any treatment with anti-mediator therapy.
Use Additional Code
Commonly Confused Codes
D47.02 (Systemic mastocytosis) also causes elevated tryptase but is a neoplastic process with bone marrow involvement.D89.41 (Monoclonal mast cell activation syndrome) requires clonal markers on mast cells rather than germline tryptase gene amplification.D89.42 (Idiopathic mast cell activation syndrome) should be reconsidered if the patient has confirmed hereditary alpha tryptasemia as the underlying cause of their symptoms.