Next-generation sequencing demonstrates the rarity of short kinase variants specific to quadruple wild-type gastrointestinal stromal tumours.

ABSTRACT

AIM: There is no known specific biomarker or genetic signal for quadruple wild-type (qWT) gastrointestinal stromal tumours (GISTs). By next-generation sequencing (NGS) of different GIST subgroups, this study aimed to characterise such a biomarker especially as a potential therapeutic target. METHODS AND RESULTS: An NGS panel of 672 kinase genes was applied to DNA extracted from 11 wild-type GISTs (including three qWT GISTs) and 5 KIT/PDGFRA mutated GISTs. Short variants which were present in qWT GISTs but no other GIST subgroup were shortlisted. After removing common population variants, in silico-classified deleterious variants were found in CSNK2A1, MERTK, RHEB, ROCK1, PIKFYVE and TRRAP. None of these variants were demonstrated in a separate cohort of four qWT GISTs. CONCLUSIONS: Short kinase variants which are specific to qWT GISTs are rare and are not universally demonstrated by this whole subgroup. It is therefore possible that the current definition of qWT GIST still covers a heterogenous population.