Optical mapping of the 22q11.2DS region reveals complex repeat structures and preferred locations for non-allelic homologous recombination (NAHR).

The most prevalent microdeletion in humans occurs at 22q11.2, a region rich in chromosome-specific low copy repeats (LCR22s). The structure of this region has defied elucidation due to its size, regional complexity, and haplotype diversity, and is not well represented in the human genome reference.