Simplified capillary electrophoresis detection of the Flt-3 internal tandem duplications and D835 point mutations in acute myeloid leukemia.

Introduction Flt-3 mutations, which include the internal tandem duplications (ITD) and missense mutations at the D835 (aspartic acid) codon,2 are arguably the most common somatic mutations in acute myeloid leukemia (AML). As relapse remains the principal cause of treatment failure for the majority of AML patients, identification of patients with a high risk of relapse would be useful for the introduction of alternative forms of therapy in this group of patients. As the presence of Flt-3/ITD is the most consistent factor in predicting relapse in AML, it is thus a valuable prognostic marker for the disease. Correlation of the D835 point mutation with poor eventfree survival suggests that it may also contribute to the constitutive activation of the Flt-3 receptor tyrosine kinase, resulting in poorer prognosis. Several independent studies have utilized polymerase chain reaction (PCR) amplification and agarose gel electrophoresis for the detection of Flt-3 gene mutations. Capillary electrophoresis (CE) was used by one group to confirm the results of ITD analysis on agarose gel. However, the use of CE as a first-line detection procedure for both ITD and point mutations has not been previously reported. We report our experience using a simplified CE-based assay for rapid detection of Flt-3/ITD and D835 mutations in 33 AML patients seen at the National University Hospital, Singapore.