A subset of the imbalances identified by CMA includes recurrent imbalances that result from rearrangements between low-copy repeats, also known as segmental duplications. These rearrangements cause genomic disorders that have been recently reviewed.48 Sharp et al. described 130 rearrangement hotspots in the human genome by defining these regions as large genomic segments (50 kb–10 Mb) that are flanked by segmental duplications ≥10 kb in size and ≥95% identical.9 Of all CNVs detected in this case cohort, ~24% result from rearrangements between segmental duplications.
