PDGFRA and Lynch syndrome: Furthermore, they showed that PDGFRA amplifications are a hallmark of pedHGG_RTK1 tumors, which often arise subsequently to cranial irradiation or in the context of a replication repair deficiency such as Lynch syndrome.39,40 Consistent with the absence of pedHGG_RTK1 gliomas, PDGFRA mutations/amplifications, which are found in up to 16% of hemispheric pedHGG,26,41 were scarce in our cohort.