Analysis of NADP+-dependent isocitrate dehydrogenase-1/2 gene mutations in pediatric brain tumors: Report of a secondary anaplastic astrocytoma carrying the IDH1 mutation

Samantha Mascelli, Alessandro Raso, Roberto Biassoni, Mariasavina Severino, Katrin Sak, Kairit Joost, Claudia Milanaccio, Salvina Barra, Filippo Grillo-Ruggieri, Irene Vanni, Alessandro Consales, Armando Cama, Valeria Capra, Paolo Nozza, Maria Luisa Garrè

Research output: Contribution to journalArticle

Abstract

Somatic mutations of the isocitrate dehydrogenase-1 gene (IDH1), most commonly resulting in replacement of arginine at position 132 by histidine (p.R132H), have been reported for WHO grade II and III diffuse gliomas and secondary glioblastomas. We investigated IDH1/2 mutations in a retrospective series of 165 pediatric brain tumors, including atypical teratoid/rhabdoid tumors (AT/RT) and choroid plexus tumors, which had not previously been investigated. Mutation analysis was performed by use of pyrosequencing and, additionally, data were validated for a cohort of 70 gliomas from among the series by use of the arrayed primer extension technique.Weidentified one tumor which harbored mutation of IDH1 at codon 132 and no alteration was identified in the matched-germline DNA. No IDH2 mutations were detected. Most noteworthy, the IDH1 mutant tumor was an anaplastic astrocytoma involving the cortex in the left frontal lobe which appeared seven years after radiation treatment for an extensive sellar/suprasellar craniopharyngioma. This anaplastic astrocytoma was regarded as secondary to radiation treatment because it seemed to originate within the irradiation field that received a dose varying from a maximum of 30.6 Gy of 4 MV X-rays down to very few Gy of lower-energy scattered radiation. In this work our observations agree with those in previous reports showing the rarity of IDH1/2 mutations in childhood tumors. The interesting identification of an IDH1 mutation in a radiation-induced secondary malignant glioma raises the likelihood that these types of tumor may develop IDH1/2 mutations. Thus, caution is needed when dealing with these tumors, and further genetic analysis is warranted.

Original languageEnglish
Pages (from-to)477-484
Number of pages8
JournalJournal of Neuro-Oncology
Volume109
Issue number3
DOIs
Publication statusPublished - Sep 2012

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Keywords

  • Choroid plexus tumors (CPT)
  • Isocitrate dehydrogenase
  • Pediatric brain tumor
  • Pyrosequencing
  • Secondary anaplastic astrocytoma

ASJC Scopus subject areas

  • Clinical Neurology
  • Cancer Research
  • Oncology
  • Neurology

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