A. Breakpoint traces in BCR intron 13 and intron 14 and in ABL1 intron 1. B. SNPs detected in individual BCR-ABL1 alleles upstream the BCR breakpoints. Dots show detected SNPs; colors of dots correspond to each patient in whom SNPs were detected; colors of BCR breakpoints indicate each patient in whom SNPs were detected; BCR breakpoints shown in black represent patients in whom SNPs were not detected; *novel SNPs (numbers indicate position in ref. seq. NG_009244.1) **minor allele in a homozygous form; BCR region sequenced in all patients; SNPs whose rs code is in red font are localized within this region. SNPs not detectable in patients because of their localization beyond the breakpoints. Twelve healthy donor samples (controls) were used as controls for SNP detection in the BCR region from exon 13 to exon 15.