Table 2. Molecular classification of GISTs (134)*.

Genetic type	Relative frequency	Anatomic distribution
KIT mutation (relative frequency 75-80%)
Exon 8	Rare	Small intestine
Exon 9 insertion AY502-503	10%	Small intestine and colon
Exon 11 (deletion, single nucleotide substitution and insertions	67%	All sites
Exon 13 K642E	1%	All sites
Exon 17 D820Y, N822K and Y823D	1%	All sites
PDGFRA mutation (relative frequency 5-8%)
Exon 12 (such as V561D)	1%	All sites
Exon 14 N659K	<1%	Stomach
Exon 18 D842V	5%	Stomach, mesentery and momentum
Exon 18 (such as deletion of amino acids IMHD 842-846	1%	All sites
KIT and PDGFRA wild-type (relative frequency 12-15%
BRAF V600E	~7-15%
SDHA, SDHB, SDHC and SDHD mutations	~2%	Stomach and small intestine
HRAS and NRAS mutation	<1%
Sporadic pediatric GISTs	~1%	Stomach
GISTs as part of the Carney triad	~1%	Stomach
NF1-related	Rare	Small intestine

Adopted from Corless and colleagues [ref (134) Table 1]. Abbreviation: GIST, gastrointestinal stromal tumor; NF1, neurofibromatosis type I; PDGFRA, platelet-derived growth factor receptor- ; SDH, succinate dehydrogenase