London, Feb 21 (ANI): It's not nervousness or a traumatic childhood but your genes that make you stutter, say scientists.
The new research has suggested that inherited mutated genes affect the brain's ability to control the voice muscles and hence result in stammering.
The findings may one day lead to new drug treatment and therapies to reverse the effects of the genetic damage.
Lead author, Dennis Drayna, of the US National Institute on Deafness and Other Communication Disorders, made the discovery after studying families in which stuttering appeared to be passed down.
He implanted the faulty human genes into mice to see how they damage the brain.
"It appears these genes are to do with brain function which suggests stuttering is physiological. The brain actually looks different in people who stutter compared with those that don't," the Telegraph quoted him as saying.
Drayna found three gene variations called GNPTAB, GNPTG and NAGPA that were common in people that have a stutter.
He believes that these genes are particularly abundant in parts of the brain that control muscle control and that the gene can cause cell death.
He suggested that this cell death could lead to a 'glitch' in the speech mechanisms, 'blocking' the ability to pronounce certain sounds and causing the stammer.
However because this physical damage is caused when children are young - up to about four years-old - when they are beginning to learn speak, it is often put down to lack of ability or intelligence.
The genes have been linked to two serious metabolic diseases known as mucolipidosis II and III, in which abnormal amounts of carbohydrates or fatty materials accumulate in cells, leading to skeletal deformities and severe learning disabilities.
The findings were discussed at the American Association for the Advancement of Science in Washington. (ANI)