RB1 and central nervous system cancer: Sequence analysis of the proband’s tumor sample showed that it carried multiple molecular alterations in addition to the PNKP mutations, including deletion of ATRX, mutations with corresponding loss of heterozygosity in TP53 and NF1, copy loss of BRCA2 and RB1, and amplification of CDK4. TP53 and ATRX mutations are commonly found in pediatric GBM54, and a recent study revealed that inactive ATRX in Trp53 deficient murine neuroepithelial progenitors (mNPCs) altered the transcriptional patterns strongly correlated with several glioma signatures55.