IDH1 and IDH2 Mutations in Gliomas

Isocitrate dehydrogenases, encoded by the IDH1 and IDH2 genes, catalyze the reduction of NADP + to NADPH in the brain. One or the other of these two genes was found to be mutated in 70% of 445 gliomas of World Health Organization grade II or III. The mutations abolished the enzymatic activity of the IDH1 and IDH2 proteins. The evidence suggests that mutation of an IDH gene is an early event in the development of gliomas. IDH1 or IDH2 genes were found to be mutated in 70% of 445 gliomas of World Health Organization grade II or III. The evidence suggests that mutation of an IDH gene is an early event in the development of gliomas. Gliomas, the most common type of primary brain tumors, are classified as grade I to grade IV on the basis of histopathological and clinical criteria established by the World Health Organization (WHO). 1 This group of tumors includes specific histologic subtypes, the most common of which are astrocytomas, oligodendrogliomas, and ependymomas. WHO grade I gliomas, often considered to be benign, are generally curable with complete surgical resection and rarely, if ever, evolve into higher-grade lesions. 2 By contrast, gliomas of WHO grade II or III are invasive, progress to higher-grade lesions, and have a poor outcome. WHO grade IV tumors (glioblastomas), the . . .