The map of human chromosomes 1, 2, and 3 shows the positions of duplications greater than 10 kilobases in size. Blue connecting lines show intrachromosomal duplications (the great majority). Interchromosomal duplications are shown with red bars. Letters A and B indicate hotspots where the recombination of duplications has given rise to genetic disorders.
[Data from J. A. Bailey et al., “Recent Segmental Duplications in the Human Genome,” Science 297, 2002, 1003–