Well, we use the word breakpoint to indicate that the human genome, which we now understand in terms of a set of chromosomes - 22 pairs plus the sex chromosomes - the x and y. The standard notion is that we have a complete set of those chromosomes and that they have a very clear structure but occasionally we see damage to those chromosomes. Sometimes we get so-called breakpoints in those chromosomes and that leads to damage at a very particular point within the genome on one or other chromosome. And it can take several different forms. It might be that you lose a whole segment of a chromosome, what we call an interstitial deletion. It might be that a piece of the DNA chromosome segment gets flipped around, a so-called inversion. Then there's a very interesting form of rearrangement, which we call a translocation, translocation moved position. So we see a piece of one chromosome move over to another chromosome and swap. So the genome is intact but there's a very precise breakpoint where there's a discontinuity in the genome from the normal.

breakpoint, chromosome, dna, interstitial, deletion, inversion, translocation, rearrangement, david, porteous