When the Human Genome Project (HPG) was hot news in the press five to ten years ago, there was a flurry of stories about a fascinating field of study called epigenetics. The epigenome, we were told, was a system whereby individual gene sequences (stretches of DNA) could be turned on or off or made to function at higher or lower levels.

These stories-also spurred by biologist Edward O. Wilson’s discussion of epigenetics in his 1998 book Consilience-tended to fall into the broad category. The peg for articles like those from Sue Goetinck for the Albany Times Union in 2003, and Sharon Begley for The Wall Street Journal in 2004, was that understanding epigenetic impacts would unlock the mysteries of diseases such as schizophrenia and certain cancers.

Readers heard a lot about the seemingly mystical area of study, with epigenetics being introduced in italics or quotation marks (or handed over to euphemisms like the headline to Begley’s Journal piece calling it “a second, secret genetic code”); these broad, introductory stories are the kind that get written when journalists don’t have a lot of focused, scientific research with which to show their subject-in this case, epigenetics-in action. And that’s fine.

Now we’re seeing epigenetics crop up in the press again. This time, specific studies abound, but that earlier, solid exposition on what epigenetics is from a broader perspective is often missing. Begley, now at Newsweek, deftly wove some key details into a likeably science-heavy study, which found that abuse may increase the risk of suicide in adults because it alters gene expression in a part of the brain associated with mental health disorders:

What the scientists did not find was any significant differences in the two groups’ gene sequences-that is, the strings of As, Ts, Cs and Gs that make up the double helix were basically the same.

But there were stark differences in the on-off setting of genes that work in the brain’s hippocampus. In the suicides, the genes were turned off like lights during a blackout, the McGill scientists report.

Unfortunately, not all reporters have the kind of familiarity with epigenetic science that allowed Begley to be so concise. Recent, longer articles about the potential link between chemical exposure and decreased male fertility gave shorter shrift to the underlying field research. The Sydney Morning Herald, for example, published a feature story in April, “Case of the disappearing dads”, that referred to the “the new science known as ‘epigenetics.’” The article had a line about the “chemical tags” that can silence or mute gene expression and a good analogy from a scientist who said, “Imagine that genes are like the hardware in a computer. Epigenetics is like the software. If you muck up either, you’ll get infertility.” But the reporter also quotes the same source saying that epigenetics “controls how tightly your DNA is packed,” which is confusing and unclear.

In February, the Guardian in London published a fluff-filled story about the same research that hardly mentioned epigenetics at all, except to say that it is “where chemicals in the environment can switch genes in the body on and off.”

The most well-known process (and unfortunately, it is often given status as the whole of epigenetic science) by which gene expression is turned “on and off” is called methylation. Such specifics are not, and should not be, beyond the public’s grasp, yet precise writing is still mostly relegated to the dedicated scientific press.

In a short article in New Scientist about the link between child abuse and suicide, Alison Motluk was able to get in a line about why one researcher thinks that the “altered methylation is the result of child abuse and not suicide itself, and is now studying suicide victims who have not suffered abuse to confirm this.”

Unfortunately, given space constraints, Motluck wasn’t able to offer much nuance. She uses the same “on-and-off switch” analogy that most journalists do, but as a Washington Post story explained, it is often not that simple; without going to either extreme, epigenetic changes can also increase or decrease the amount of expression in a specific set of genes like a volume knob. The article also offered a synopsis of the knob’s mechanics:

Epigenetic changes are basically changes in the structure of the DNA that occur when the cell divides and the DNA is replicated. These changes interfere with the ability of DNA to be transcribed, or send messages out to the rest of the body…

Russ Juskalian is a contributor to The Observatory and a freelance writer.