Sequencing of neuroblastoma identifies chromothripsis and defects in neuritogenesis genes

Abstract

Whole-genome sequencing of neuroblastoma, a childhood tumour of the nervous system, shows that chromothripsis (a local shredding of chromosomes) and mutations in genes regulating neurite growth are associated with the most aggressive tumours. Whole-genome sequencing is used here to identify genetic defects in 87 people with neuroblastoma, a childhood tumour of the peripheral sympathetic nervous system. Analyses revealed few recurrent amino-acid-changing mutations, but a series of genes functioning in neuritogenesis and extension of neuronal growth cones were deleted in aggressive high-stage tumours. Chromothripsis, the localized shattering of the chromosomes, was common in high-stage tumours and was generally associated with poor prognosis. Neuroblastoma is a childhood tumour of the peripheral sympathetic nervous system. The pathogenesis has for a long time been quite enigmatic, as only very few gene defects were identified in this often lethal tumour1. Frequently detected gene alterations are limited to MYCN amplification (20%) and ALK activations (7%)2,3,4,5. Here we present a whole-genome sequence analysis of 87 neuroblastoma of all stages. Few recurrent amino-acid-changing mutations were found. In contrast, analysis of structural defects identified a local shredding of chromosomes, known as chromothripsis, in 18% of high-stage neuroblastoma6. These tumours are associated with a poor outcome. Structural alterations recurrently affected ODZ3, PTPRD and CSMD1, which are involved in neuronal growth cone stabilization7,8,9. In addition, ATRX, TIAM1 and a series of regulators of the Rac/Rho pathway were mutated, further implicating defects in neuritogenesis in neuroblastoma. Most tumours with defects in these genes were aggressive high-stage neuroblastomas, but did not carry MYCN amplifications. The genomic landscape of neuroblastoma therefore reveals two novel molecular defects, chromothripsis and neuritogenesis gene alterations, which frequently occur in high-risk tumours.