These were PDX models harboring primary and secondary <i>KIT</i> and additional mutations; <i>KIT</i> exon 11 (p.Y570_L576del), <i>KIT</i> exon 17 (p.D816E), and <i>PTEN</i> (p.T321fs) mutations in GIST-RX1 from a patient who was unresponsive to imatinib, sunitinib, and sorafenib, and <i>KIT</i> exon 11 (p.K550_splice) and <i>KIT</i> exon 14 (p.T670I) mutations in GIST-RX2 and <i>KIT</i> exon 9 (p.502_503insYA) and <i>KIT</i> exon 17 (p.D820E) mutations in GIST-RX4 from patients with imatinib and imatinib/sunitinib resistance, respectively.
The present case is the first proven case of multiple GIST with a c-kit germline mutation in Korea and is distinguishable from other reported germ-line c-kit mutations because the same 1676 T --> C missense mutation occurs in the normal allele as well as the affected allele, although the significance of the identical mutations remains to be investigated.
A KIT mutation was identified in six cases (67%), including three with the D816V mutation typical of adult-onset disease, and another three with an internal tandem duplication (p.A502_Y503dup) in exon 9, previously described in gastrointestinal stromal tumour.
A KIT mutation was identified in six cases (67%), including three with the D816V mutation typical of adult-onset disease, and another three with an internal tandem duplication (p.A502_Y503dup) in exon 9, previously described in gastrointestinal stromal tumour.
Whereas KIT juxtamembrane domain mutations seen in most patients with GIST are highly sensitive to imatinib, the kinase activation loop mutant D816V, frequently encountered in SM, hampers the binding ability of imatinib.
Whereas KIT juxtamembrane domain mutations seen in most patients with GIST are highly sensitive to imatinib, the kinase activation loop mutant D816V, frequently encountered in SM, hampers the binding ability of imatinib.