Acute Myeloid Leukemia With IDH1 or IDH2 Mutation Frequency and Clinicopathologic Features

Mutations in the isocitrate dehydrogenase 1 (1DH1) and IDH2 genes are reported in acute myeloid leukemia (AML). We studied the frequency and the clinicopathologic features of IDH1 and IDH2 mutations in AML. Mutations in IDH1 (IDH1(R132)) and IDH2 (1DH2(R172)) were assessed by Sanger sequencing in 199 AML cases. Point mutations in IDH1 1132 were detected in 12 (6.0%) of 199 cases and in IDH2(R172) in 4 (2.0%) of 196 cases. Of the 16 mutated cases, 15 (94%) were cytogenetically normal, for an overall frequency in this group of 11.8%. IDH1(R132) and IDH2(R172) mutations were mutually exclusive. Concurrent mutations in NPM1, FLT3, CEBPA, and NRAS were detected only in AML with the IDH1(R132) imitation. The clinical and laboratory variables of patients with AML with IDH mutations showed no significant differences compared with patients with wild-type IDH. We conclude that IDH1(R132) and IDH2(R172) imitations occur most often in cytogenetically normal AML cases with an overall frequency of approximately 11.8%.