The Distribution and Significance of IDH Mutations in Gliomas

The discovery of somatic isocitrate dehydrogenase (IDH) mutations in gliomas is an example of the powerful impact of the next-generation sequencing on the comprehension of both tumor biology and human diseases. IDHs catalyze the oxidative decarboxylation of isocitrate to α-ketoglutarate with production of NADH/NADPH. Thus, they are key enzymes in the Krebs cycle. For this family of metabolic genes, no previous role in human cancer has been described. However, in a recent genomewide study, recurrent somatic mutations in the IDH1 gene have been identified in patients affected by Glioblastoma Multiforme (GBM) [1]. In successive studies, IDH mutations have also been found in low-grade gliomas, as well as in acute myeloid leukemia. The aim of this chapter is to review the findings on the epidemiology and significance of IDH mutations in human gliomas, from the discovery to the current knowledge about their molecular pathogenesis. Special attention will be paid to the powerful diagnostic and prognostic relevance of the IDH mutations in the clinical practice of neuro-oncology.