These tumors are currently defined by having no mutations in exons 9, 11, 13, and 17 of the KIT gene and exons 12, 14, and 18 of the PDGFRA gene.
Примерно 85 % ГИСО у детей и 10—15 % ГИСО у взрослых не несут мутаций в экзонах 9, 11, 13 и 17 гена "KIT" и экзонах 12, 14 и 18 гена "PDGFRA".