Fig. 4

Validation of selected somatic mutations by Sanger sequencing on FF and FFPE tumor DNA and on PB-derived DNA. a PDGFRA p.D842V mutation detected in GIST165 tumor DNA from FF and FFPE samples. b KIT p.L576P mutation present in GIST174 patient, both in FF and FFPE. c SDHA p.S384X detected in patient GIST193 in heterozygosis in the germline, and in homozygosis in tumor DNA (both from FF and FFPE). d False negative LATS2 p.Q937X somatic stop-gain mutation. This mutation is present in both FF and FFPE samples, but fails to be detected by WES of FFPE due to low coverage. e False positive GPR45 p.V203M missense variant. This putative mutation is a present only in FFPE and not in FF sample from GIST127, probably due to cytosine deamination induced by formalin fixation