LONDON (REUTERS) - No matter who you are, for most of us grey hair is an inevitable part of getting older.

But what if you could switch off the gene that causes it?

For the first time, scientists have identified a gene called IRF4 as the culprit behind grey hair.

DNA samples from over 6,000 volunteers were collected in Latin America; chosen for the diverse ancestry of its inhabitants.

And it turns out if you have your roots in Europe, grey hair is much more likely.

"This genetic variant of IRF4 has two forms; one form is present worldwide and the other form is present only in Europeans. And we saw that this particular European specific form gives you almost double the chance of hair greying," said Dr Kaustubh Adhikari from the Cell and Developmental Biology department of University College London.

The gene IRF4 helps regulate melanin in the body, which determines - among other things - hair colour. Age and environmental factors will, of course, influence how quickly IRF4 triggers hair greying.

But the researchers say their discovery could lead to a treatment that could stop it in its tracks.

"Switching off a gene is of course feasible, the issue is whether it will have the desired effect and whether it's the right thing to do... But in terms of trying to develop a therapy to delay or prevent hair greying, that is something that is potentially feasible; yes," said Professor Andres Ruiz-linares from the Biosciences department of University College London.

That could be music to the ears for many, though the mood was decidedly pro-grey in a market in London.

"I don't mind going grey, I don't mind not going grey - I really couldn't care less," said a male shopper.

"Go grey. Definitely go grey, go natural," a female shopper said.

Scientists say a simple cosmetic treatment for switching off the grey gene would take many more years of research.

But for those keen to banish the grey forever, your prayers might one day be answered.