Can Geneticists Fight Disease by Targeting ‘Nurture’ Instead of ‘Nature’?

It is one of biology’s most ingenious rhythms: Every baby is born young. No matter how much wear and tear their parents’ DNA accumulated over their lifetimes, reproduction erases the molecular scars, handing a clean slate to the next generation.

Now, a new frontier in biotechnology aims to harness this natural mechanism to do something once thought impossible: scrub away the biological detritus of our own past. By mimicking Mother Nature’s magic eraser, geneticists are working to open a new avenue for treating or preventing disease later in life — not by editing genes themselves, but by altering when, where and how genes are expressed.

All of this is possible thanks to the epigenome, a network of chemical tags throughout the body that latch on to DNA and tell each cell type how to behave. If a person’s DNA is a string of notes in a musical score, the epigenome is the collection of the conductor’s pencil markings left on the page — accumulated through experience over time, indicating which notes to play louder or softer or to skip entirely...