Genescan analysis of FLT3/ITD levels.

The PCR assay was performed with fluorescein-labeled primers and analyzed with an automated DNA sequencer. The area under the curve was calculated for each allele using Genescan software (see “Materials and methods”). M1-M3 indicates FLT3/ITD mutations of different sizes and levels; W, wild-type FLT3. (A) Patient 22 had 2 mutations at diagnosis, with only the dominant mutation (M2) detected at relapse at an increased level.(B) Patient 23 also had 2 mutations at diagnosis, but lost the minor one (M2) while acquiring a new dominant clone (M3) at relapse. (C) Patient 24 had 3 mutations at diagnosis, losing 2 (M1 and M2) and harboring only M3 at a higher level at first relapse, which increased further at second relapse. (D) Patient 25 had a single mutation at diagnosis, acquiring another one (M2) at first relapse, which was the only mutation at second relapse.