title: Genomic BCR-ABL1 breakpoints in pediatric chronic myeloid leukemia.
abstract: Chronic myeloid leukemia (CML) is a rare disease in children and adolescents and various aspects-from molecular genesis to therapy regimen-have been taken over from studies on the more prevalent adult CML. However, differences have been observed between malignancies with identical underlying chromosomal translocations, but occurring at different age groups, suggesting some diversity in the mechanisms of formation and leukemogenesis. A multiplex long-range PCR-based assay was developed to allow fast and reliable amplification of patient-specific BCR-ABL1 fusion sequences from genomic DNA. The localization of breakpoints was analyzed with respect to distribution within the breakpoint cluster regions, sequence features, and association to repetitive elements or motifs associated with DNA recombination. The genomic fusion sites of 59 pediatric CML patients showed a bimodal breakpoint distribution in BCR that was different from the distribution in adult CML cases, but with similarities to BCR-ABL1-positive, acute lymphoblastic leukemia in adults. BCR breakpoints were found more frequently positioned within, or close to, Alu repeats than would be expected based on their overall sequence proportion. Technical aspects of the highly sensitive DNA-based quantification of residual CML cells by specific fusion sequence during tyrosine kinase inhibitor therapy are exemplified in a subcohort of pediatric CML patients.
authors.affiliation: Department of Pediatrics, University Hospital Erlangen, Germany.
authors.forename: Manuela
authors.initials: M
authors.lastname: Krumbholz
authors.forename: Matthias
authors.initials: M
authors.lastname: Karl
authors.forename: Josephine T
authors.initials: JT
authors.lastname: Tauer
authors.forename: Christian
authors.initials: C
authors.lastname: Thiede
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Rascher
authors.forename: Meinolf
authors.initials: M
authors.lastname: Suttorp
authors.forename: Markus
authors.initials: M
authors.lastname: Metzler
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D056905:Chromosome Breakpoints; D015331:Cohort Studies; D004273:DNA, Neoplasm / Q000737:chemistry / Q000235:genetics; D005260:Female; D016044:Fusion Proteins, bcr-abl / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D007223:Infant; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000235:genetics*; D008297:Male; D012333:RNA, Messenger / Q000032:analysis; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D004273:DNA, Neoplasm; D012333:RNA, Messenger; D016044:Fusion Proteins, bcr-abl