Stuttering is in the genes, and has nothing to do with nervousness or a traumatic childhood as perceived, says a new study.
Researchers have carried out the study and found that mutated genes which are inherited are more likely to be the blame for stuttering, affecting the brain’s ability to control the voice muscles.
According to them, the finding could lead to new drug treatment and therapies to reverse the effects of the genetic damage, the Daily Telegraph reported.
The researchers, led by Dr 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.
In their study, they have implanted the faulty human genes into mice to see how they damage the brain. “It is a really exciting time in the science of stuttering. It appears these genes are to do with brain function which suggests stuttering is physiological. The brain actually looks different in people who stutter,” he said. The researchers found three gene variations called GNPTAB, GNPTG and NAGPA, that were common in people that have a stutter.
They believe these genes are particularly abundant in parts of the brain that control muscle control and that the gene can cause cell death. They suggest 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. In fact, the researchers tracked down the genes in Pakistan where they found an extended family with a lot of stutterers. The genes have been linked to two serious metabolic diseases known as mucolipidosis II and III, in which abnormal amount of carbohydrates or fatty materials accumulate in cells leading to skeletal deformities and learning disabilities.