[Clinical characteristics in adult acute myeloid leukemia with isocitrate dehydrogenase gene mutation]

To explore the prevalence and clinical characteristics of isocitrate dehydrogenase (IDH)1 R132 and IDH2 R140/R172 gene mutations in acute myeloid leukemia (AML) patients.

Polymerase chain reaction (PCR) and direct sequencing were used to sequence exon 4 of IDH gene in 570 AML patients from 2005 to 2011.

In a cohort of 570 patients, AML IDH gene mutation was found in 90 (15.79%) patients. IDH1 and IDH2 mutations were detected in 27 (4.74%) patients and 63 (11.05%) patients respectively. None of them had the combined mutations of IDH1 and IDH2. The highest frequency of IDH mutations was found in AML M1 (according to the FAB scheme) compared with all other subtypes (P < 0.01). The median age was 53 years in mutated group versus 40 years in wild-type group (P = 0.010). Mutated and wild-type groups had no significant difference in gender, white blood cell count at diagnosis, hemoglobin count and bone marrow blast percentage, excepting for blood platelets level (median 52×10(9)/L vs 31×10(9)/L, P < 0.01). IDH gene mutations were associated with cytogenetically normal (CN)-AML, NPM1 mutations and particularly with the genotype of mutated NPM1 without FLT3-ITD. IDH gene mutations had no significant correlation with WT1, FLT3-TKD and MLL-PTD mutations. IDH mutated patients had a lower complete remission rate than unmutated in non-M3 patients (58.1% vs 77.9%, P < 0.05). And the patients with mutant IDH gene were associated with a shorter overall survival (28.4% vs 51.3%, P < 0.01).

IDH gene mutations are more prevalent in elder AML patients and it may constitute a molecular marker for a poor prognosis in AML.