title: Detection of IDH1 and IDH2 mutations by fluorescence melting curve analysis as a diagnostic tool for brain biopsies.
abstract: Novel mutations in the isocitrate dehydrogenase 1 (IDH1) and 2 (IDH2) genes have been identified in a large proportion of diffuse gliomas. Tumors with IDH1/2 mutations have distinctive clinical characteristics, including a less aggressive course. The aim of this study was to develop and evaluate the performance of a novel real-time PCR and post-PCR fluorescence melting curve analysis assay for the detection of IDH1 and IDH2 mutations in routine formalin-fixed, paraffin-embedded tissues of brain biopsies. Using the established assay, we tested 67 glial neoplasms, 57 non-neoplastic conditions that can often mimic gliomas (eg, radiation changes, viral infections, infarctions, etc), and 44 noncentral nervous system tumors. IDH1 and IDH2 mutations were detected in 72% of lower grade diffuse gliomas and in 17% of glioblastomas. The IDH1 mutation was the most common (93%), with the most frequent subtype being R132H (88%). These mutations were not identified in non-neoplastic glioma mimickers and in noncentral nervous system tumors including thyroid carcinomas. The results of this assay had a 100% correlation with the results obtained by conventional sequencing. In summary, we report here the real-time PCR/fluorescence melting curve analysis assay that provides rapid and sensitive detection of IDH mutations in formalin-fixed, paraffin-embedded tissues, and is therefore useful as a powerful adjunct diagnostic tool for refining histopathological diagnosis of brain lesions and guiding patient management.
authors.affiliation: Department of Pathology, University of Kentucky, Lexington, Kentucky, USA.
authors.forename: Craig
authors.initials: C
authors.lastname: Horbinski
authors.forename: Lindsey
authors.initials: L
authors.lastname: Kelly
authors.forename: Yuri E
authors.initials: YE
authors.lastname: Nikiforov
authors.forename: Mary Beth
authors.initials: MB
authors.lastname: Durso
authors.forename: Marina N
authors.initials: MN
authors.lastname: Nikiforova
mesh_terms: D001483:Base Sequence; D001706:Biopsy; D001921:Brain / Q000473:pathology*; D004252:DNA Mutational Analysis / Q000379:methods*; D017931:DNA Primers / Q000378:metabolism; D005453:Fluorescence; D005910:Glioma / Q000175:diagnosis* / Q000201:enzymology / Q000235:genetics; D006801:Humans; D007521:Isocitrate Dehydrogenase / Q000235:genetics*; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics*; D009691:Nucleic Acid Denaturation / Q000235:genetics*; D016133:Polymerase Chain Reaction
chemical_list: D017931:DNA Primers; C538784:IDH2 protein, human; D007521:Isocitrate Dehydrogenase; C543588:IDH1 protein, human