highly significantp < 10 −5
Localized rearrangements on a per-chromosome basis were identified using previously established metrics 19 : the presence of chromosomes that had a highly significant non-random distribution of breakpoints with a threshold of p < 10 −5 were considered to be clustered and chromosomes with high numbers of rearrangement events were identified as outliers defined as a breakpoint per megabase rate exceeding 1.5 times the length of the inter-quartile range from the seventy-fifth percentile for each sample with a minimum threshold of 35 breakpoints per chromosome.