June 27, 2019 – Mosaic


Anchor lead: Your DNA is a lot more random than you might think, Elizabeth Tracey reports

DNA is neatly packaged and essentially the same all over your body, right? Wrong, increasing evidence shows. Cristian Tomasetti, a cancer researcher at Johns Hopkins, says the term used to describe the actually quite variable DNA sequencing with its full range of mutations is mosaic.

Tomasetti: Mosaic means that when you look at a tissue you are going to find essentially different regions containing different mutation types. So it’s not uniform. As we age this mosaicism keeps growing, keeps getting more intense. It’s also the clones that you create. Essentially a sack of cells that have the same mutation as that mother cell. And if it’s a driver gene driving cancer, now that group of cells is one step closer to cancer.   :32

Tomasetti says this observation has implications for new cancer screening tests that look for mutations. At Johns Hopkins, I’m Elizabeth Tracey.