FLT3 internal tandem duplication and FLT3-D835 mutation in 80 AML patients categorized into cytogenetic risk groups

Acute myeloid leukemia (AML) is a clonal disorder characterized by various genetic abnormalities and variable response to treatment. About 50% of patients with AML have no cytogenetic aberrations, presenting normal karyotype, and are categorized in the intermediate risk group. In this group detection of FLT3 mutations move a patient from the intermediate to the adverse risk group.

Bone marrow from 80 AML patients was cultured to obtain chromosome slides and then karyotype. Simultaneously DNA was isolated from bone marrow and PCR reaction was conducted to test the FLT3 mutation status (ITD and D835). For statistical analysis Chi squared test was used.

From the group of 80 AML patients seven were classified as a favorable risk group and FLT3/ITD was found only in one of these patients (14.28%), and FLT3/D835 in another one (14.28%). Fifteen patients showed a complex karyotype with more than three aberrations or with any aberration known as a poor prognosis. Among the adverse group FLT3/ITD was detected in three patients (20%) and D835 mutation in two other patients (13.33%). Among 58 patients with normal karyotype in GTG banding FLT3/ITD occurred in six cases (10.34%) and D835 mutation in two cases (3.45%). No significant difference was found among these three risk groups regarding presence or absence of FLT3/ITD and FLT/D835.

Molecular characterization of mutations in several genes, such as FLT3, NPM1, MLL, CEBPA, in acute myeloid leukemia, especially in normal karyotype cases, could be another factor after cytogenetic analysis to stratify AML patients into different prognostic categories.