Interestingly, the majority, 12 PGVs in 10 patients, were in established cancer predisposition genes with a strong association with familial glioblastoma (MSH6 (3x), PMS2 (5x), MSH2, NF1 and BRCA1) or with medulloblastoma (SUFU). The gene discussed is MSH2; the disease is medulloblastoma.