Pyrosequencing of IDH1 and IDH2 Mutations in Brain Tumors and Non-neoplastic ConditionsCykowski, Matthew D. MD; Allen, Richard A. MS; Fung, Kar-Ming MD, PhD; Harmon, Michael A. BS; Dunn, Samuel T. PhDDiagnostic Molecular Pathology: December 2012 - Volume 21 - Issue 4 - p 214–220 doi: 10.1097/PDM.0b013e31825d802b Original Articles Buy Abstract Author Information The molecular profiling of brain tumors, including testing for MGMT promoter methylation and chromosome 1p/19q deletion, can provide both diagnostic and prognostic information that may guide treatment. Isocitrate dehydrogenase (IDH) mutation testing is a recent addition to this armamentarium of molecular pathology tools that similarly provides both diagnostic (eg, glioma vs. gliosis) and prognostic information. Herein, we describe a pyrosequencing-based approach to IDH1 and IDH2 mutation testing and its application to 139 neoplastic and non-neoplastic central nervous system specimens. Several technical issues encountered in the development of the assay, particularly with regard to the optimization of the sequencing reaction, are described. Mutations in IDH1 codon 132 or IDH2 codon 172 were identified in 31.2% of all screened cases and 46.2% of screened World Health Organization grade I to IV gliomas (n=93), with mutations arising exclusively in grade II to IV oligodendroglial, astrocytic, or mixed oligoastrocytic neoplasms. Examination of the relationship between the mutation status and other pertinent variables demonstrated a significant male predominance among IDH1-mutated gliomas, most notably in grade III to IV astrocytic neoplasms. A significant association between IDH1/IDH2 mutation and 1p/19q deletion was also seen (Kendall τ coefficient=0.26, P=0.018), although several cases with 1p/19q deletion were IDH1/IDH2 wild type. Department of Pathology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma The authors declare no conflict of interest. Reprints: Samuel T. Dunn, PhD, Department of Pathology, The University of Oklahoma Health Sciences Center, 940 Stanton L. Young Blvd., BMSB 451, Oklahoma City, Oklahoma 73104 (e-mail: Terence-Dunn@ouhsc.edu). © 2012 Lippincott Williams & Wilkins, Inc.