Isocitrate dehydrogenase (IDH) catalyzes the conversion of isocitrate to alpha ketoglutarate. IDH occurs in three isoforms, IDH1, located in the cytoplasm, IDH2 located in the mitochondria, and IDH3, which functions as part of the TCA cycle. Mutations in the active site of IDH1 at position R132 and an analogous mutation in the IDH2 gene at position R172 have been discovered. Notably, many cases of acute myeloid leukemia (AML) have mutations in R172 and R140. The impact of these mutations and early results of inhibiting mutant IDH2 with the reversible inhibitor AG-221 are discussed in this review.
