Gene

SRSF2

1 variant(s) documented across Systemic Mastocytosis

Variants

Variant	Type	Frequency in disease	Significance	Also found in
Various (most commonly P95H/L/R)	somatic	~43% of advanced SM	Splicing factor mutation. Strongest individual predictor of inferior survival in advanced SM (HR 5.9). Part of the S/A/R gene panel.	MDS/CMML (~15-50%)

Various (most commonly P95H/L/R)

High-risk mutation. Predicts poor prognosis and may predict inferior response to midostaurin.

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