Fig. 1: ATRX mutations are mutually exclusive of MYCN amplification in neuroblastoma.

a Summary of ATRX mutations in the COG and PCGP cohorts. Black bars indicate the deleted amino acids; red indicates nonsense mutations; orange indicates frameshift mutations; and blue indicates missense mutations. The major protein domains are shaded in blue. b Bar plot of the percentage of the 819 patients analyzed in this study with ATRX mutations for each age and stage. c, d EFS for patients with neuroblastoma with or without ATRX mutations for stages 1–3 or stage 4 for all age groups. P values were calculated using Cox model. e Heatmap of the distribution of mutations in MYCN, ATRX, and ALK in the COG cohort. Only those tumors with a mutation in at least one of the three genes are indicated. f Micrograph of MYCN FISH (red) for the one neuroblastoma sample with an ATRX mutation and MYCN amplification showing regional amplification (dashed line). The PAX3 (2q35) probe (green) is the control. g Micrograph of a neuroblastoma cell with MYCN homogenously staining region within a region of the tumor that has MYCN amplification (box within the dashed line region in f. h Micrograph of a neuroblastoma cell with two copies of MYCN outside of the region with amplification (box outside of the dashed line region). i Representative photograph of neuroblastoma tumors from a LSL-MYCN;Dbh-iCre mouse. All the tumors developed in this mouse cohorts were harvested and examined. j Micrographs of the histology of the tumor shown in i. The boxed region in each micrograph is magnified in the lower left panel of each image. Three tumors from each group of mice were examined by both H&E and immune-staining. k, l Survival curves for two mouse models of neuroblastoma with or without conditional ATRX deletion. The numbers of mice in each group are indicated. P values were calculated using Log-rank test. Scale bar: f, 5 μm, g, h, 1 μm. COG Children’s Oncology Group, PCGP Pediatric Cancer Genome Project, INSS International Neuroblastoma Staging System, H&E hematoxylin and eosin, TH tyrosine hydroxylase.