Three genes have been found by researchers from the National Institutes of Health (NIH) that might cause people to stammer. This condition affects five per cent of young kids and about three million Americans.

Investigators with the NIH's National Institute on Deafness and Other Communication Disorders (NIDCD) established gene mutations that trigger stammering.

Jane Fraser, president of the support and education group Stammering Foundation of America, stated that these findings were beneficial for people who stammer.

Fraser added, "For adults who stammer this is huge because it proves there is a biological reason for stammering. So many people who stammer feel extreme guilt and think that if they just tried harder they could get over it."

About 46 Pakistani families were studied by NIDCD geneticist Dennis Drayna, PhD, and colleague. These families had large number of people who stammered.

In the family members who stammered researchers identified mutations in a gene known as GNPTAB. They also studied for these gene mutations in 46 stammerers from the original families and 77 Pakistani stammerers who did not belong to these families.

It was found that in many of those who stammered GNPTAB mutations were present but it was not present in non-stammerers.