MRD-quantification during treatment of ETV6-RUNX1 positive ALL relapses using the genomic breakpoint of the fusion gene

T-cell receptor (TCR)/Immunoglobulin(IG)-gene rearrangements used as minimal residual disease (MRD) markers in acute lymphoblastic leukaemia (ALL) can describe different subclones at initial/relapse diagnosis because leukaemic clones are exposed to influences of clonal evolution and selection during/after treatment. We aimed at investigating whether the genomic breakpoint of the fusion gene ETV6-RUNX1 (E/R) is a suitable MRD-marker. Patients with an E/R positive first ALL relapse were included in the study (n=76). Identification and sequencing of the breakpoint was performed using nested multiplex long-range PCR…