Acquired somatic mutations of isocitrate dehydrogenases 1 and 2 (IDH1 and IDH2) in preleukemic disorders

Mutations of isocitrate dehydrogenase isoform 1 and 2 (IDH1 and IDH2) genes have been identified in glioblastoma and acute myeloid leukemia (AML). However, little is known about the molecular alterations of IDH genes in preleukemic disorders with a propensity to transform to AML. We performed polymerase chain reaction-denaturing high performance liquid chromatography (PCR-DHPLC) followed by direct sequencing to detect IDH mutations in 237 patients with myeloproliferative neoplasms (MPNs; n=108), myelodysplastic syndrome (MDS; n=22), paroxysmal nocturnal hemoglobinuria (PNH; n=41), and aplastic anemia (AA; n=66). No IDH1 R132 and IDH2 R172 mutations were identified in the entire cohort, whereas IDH1 G105G allele was detected in 4/108 MPN (3.70%), 2/22 MDS (9.09%), and 2/41 PNH (4.88%) patients. Three IDH2 R140Q mutations were found in 2/108 MPN (1.85%) and 1/22 MDS (4.54%) patients, while one IDH2 G145G allele was found in 0.92% (1/108) of MPN patients. Overall, our data suggest that IDH mutations are rare in the preleukemic disorders and may not be the major initial step in AML leukemogenesis.