Table 3.

Common indications for genetic testing for hereditary alpha tryptasemia

sBT level ≥ 8 ng/mL
Recurrent signs of MC activation with unclear etiology (such as idiopathic anaphylaxis)
Suspected SM with negative c-KIT D816V, but very high TPS level
SM or MCAS with severe mediator-related symptoms
Serum TPS value > 15.0 ng/mL without underlying mastocytosis or myeloid neoplasm
Familial clustering of systemic MC activation symptoms
Higher levels of sBT according to the degree of bone marrow mast cell infiltration
Diagnosed or suspected idiopathic or secondary MCAS

MC: Mast cell; MCAS: Mast cell activation syndrome; sBT: Serum basal tryptase; SM: Systemic mastocytosis; TPS: Tryptase; KIT: Tyrosine kinase protein.