Terminologies about hyper mutation

Question

[mangfu100]

Hi all.

I am having a question about hyper mutations.

While I am reading a paper (http://www.nature.com/nature/journal/v500/n7463/full/nature12477.html)

the terminology (localized substitution hypermutations) is something strange to me. Even though I searched it on the Internet, but I failed to fully understand its concept. There are too many articles and web pages related to its definition and explanation.

What I didn't understand is below sentence in the paper.

Foci of localized substitution hypermutation, termed kategis after the Grrek for thunderstorm were recently described in breast cancer.

It is hard to know what is localized substitution hyper mutation.

I really appreciate it if you help me understand its concept :)

Answer 1

[DG]

Take a look at Figure 6 of that paper, which shows rainfall plots illustrating this phenomenon in three different tumour samples, each from a different type of cancer. The whole genome is essentially spread across the Y axis, while the Y axis represents a mutations distance from the "previous" mutation when you construct a genome scan. You can see some clusters of mutations that are all grouped together in close genomic proximity to each other. So you have hypermutation, but within localized regions of the genome.