Gene

RUNX1

1 variant(s) documented across Systemic Mastocytosis

Variants

Variant	Type	Frequency in disease	Significance	Also found in
Various	somatic	~23% of advanced SM	Transcription factor essential for hematopoiesis. Mutations predict inferior survival (HR 2.4). Part of the S/A/R gene panel.	AML (~10-15%); MDS (~10%)

Various

High-risk mutation. Contributes to multi-mutated stem cell disease phenotype.

Testing: next-generation sequencing

Hereditary alpha-tryptasemia (HαT) modifies SM phenotype, increasing mediator symptoms and anaphylaxis risk independent of mast cell burden

emerging·6 studies