We also found a very rare subset of cells that had extreme levels of aneuploidy, and to our eyes, were largely indistinguishable from breast cancer genomes.

These changes are strikingly similar to some common alterations found in breast cancers (gains of 1q, losses on 16q, 22)

We found chromosomal abnormalities occur at a low but appreciable level in all individuals (both BRCA carriers and non-carriers).