This is a multicenter screening study to characterize the prevalence of the KIT D816V mutation in participants with suspected clonal mast cell disease.
Documented anaphylaxis due to Hymenoptera venom with cardiovascular symptoms or
Documented anaphylaxis without known trigger(s) or allergen(s) warranting hospitalization, emergency room visit, and/or epinephrine with cardiovascular symptoms 2. SMAC-B
Episodic or recurrent signs and symptoms consistent with mast cell activation without known triggers or allergens in at least 2 of the following organ systems: skin, respiratory/naso-ocular, gastrointestinal tract, or cardiovascular.
Any clinical response on one or more optimally dosed therapies intended to mitigate mast cell mediators, as determined by the Investigator.
Monoclonal mast cell activation syndrome with a known KIT mutation
Cutaneous mastocytosis only (that is, no documentation of systemic mast cell disease via bone marrow biopsy)
Any subtype of systemic mastocytosis
Mast cell sarcoma