disease has basis in disruption of disease caused by disruption of mast cell activation disease leukocyte disorder mast cell activation syndrome 2018-07-17T21:32:53Z https://github.com/monarch-initiative/mondo/issues/5537 MONDO:0100004 MEDGEN:1698540 MACS A clinically defined disease states with a largely unknown morphological background. Acute mast cell activation (MCA) is commonly seen in allergic reactions and often leads to the clinical signs and symptoms of anaphylaxis. Severe or even life‐threatening MCA may occur when the burden of mast cells is high and/or these cells are in an hyperactivated state. Mastocytosis may be associated with mast cell activation syndrome (MCAS). GARD:0012981 mast cell activation disease disorder of mast cell activation UMLS:C5200989 MESH:D000090267