A TP53 mutation was found in a 1-year-old girl with AML, a TNNT2 mutation associated with dilated cardiomyopathy was found in a 15-year-old boy with osteosarcoma, a RYR1 mutation associated with malignant hyperthermia was found in a 7-year-old girl with neuroblastoma, and a mutation in VHL was found in a 2-year-old boy with ependymoma. The gene discussed is RYR1; the disease is ependymoma.