has characteristic has characteristic mast cell activation syndrome idiopathic mast cell activation syndrome 2018-07-17T21:46:53Z https://github.com/monarch-initiative/mondo/issues/9097 MEDGEN:1786072 ICD10CM:D89.42 GARD:0026026 idiopathic MACS Mast cell activation syndrome where neither an allergy or other underlying disease is association, nor KIT-mutated mast cells are detectable. MONDO:0100051 UMLS:C4267894 idiopathic idiopathic disease