IDH mutation
A genetic alteration in isocitrate dehydrogenase genes that defines distinct molecular subgroups of gliomas with prognostic significance.
Full Definition
IDH mutation refers to alterations in the isocitrate dehydrogenase genes (IDH1 and IDH2) that occur in a subset of gliomas, particularly lower-grade gliomas and secondary glioblastomas. These mutations result in the production of the oncometabolite 2-hydroxyglutarate, leading to widespread epigenetic changes and the CpG island methylator phenotype (G-CIMP). IDH-mutant gliomas represent a distinct molecular entity with significantly better prognosis than IDH-wildtype tumors. This biomarker is now integral to the WHO classification of brain tumors and influences treatment decisions and clinical trial stratification.
Usage
Usage note: Specify IDH1 R132H when this common variant is identified.
In Context
- "The glioma demonstrated IDH mutation with favorable prognostic implications." — molecular pathology report
- "IDH mutation status is now required for accurate WHO classification of diffuse gliomas." — neuropathology guideline