Copy number analysis of the IKZF1 locus in DNA at diagnosis with the use of CNAG 3.0. The blue lines indicate the mean CNA of 5 contiguous SNPs. The numbers 0, 2, and 4 refer to the genomic copy number. (A-C) The bold arrows point to the IKZF1 locus. (C) The fine dotted arrows indicate the genomic breakpoints (base pair location, NCBI35/Hg17) around the IKZF1 gene. (A) Twin 1A, (B) twin 1B, (C) twin 2A, and (D) twin 1A, IKZF1 sequence.