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
History of at least one event of anaphylaxis as determined by the Investigator's clinical assessment and judgment based on available medical history, clinical presentation, and supporting documentation without a clearly identifiable trigger(s) or allergen(s) (otherwise idiopathic anaphylaxis) OR
SMAC-AGS: History of anaphylaxis after eating mammalian meat (e.g. pork, beef) AND history of elevated alpha-gal (galactose-alpha 1, 3 galactose) serum IgE as determined by the Investigator's clinical assessment and supporting medical history documentation 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.
Monoclonal mast cell activation syndrome with a known KIT mutation
Any subtype of systemic mastocytosis
Mast cell sarcoma
Cohort 2 only: Osteopenia or osteoporosis attributed to known genetic, endocrine, nutritional, or other medical conditions.