TECHNOLOGY FOR CHANGE

While Too Late for King George, Researchers Find Links to Stuttering

Salvatore Salamone | Date: 03-01-11 | Comments

The Academy Award-winning "The King�s Speech" highlighted one of the many �cures� that have been tried over the years to help stutterers. Now researchers are looking for stuttering�s genetic and biological root causes to develop suitable treatments.

Thanks to "The King�s Speech," stuttering got prominent attention at this week�s Academy Awards show. But it was also in the spotlight at last week�s American Association for the Advancement of Science (AAAS) annual conference, held in Washington, DC.

At the conference, scientists discussed the latest techniques being applied to the study of stuttering. The ultimate goal is to find a biological model that will explain why stuttering starts when it does, why some people are more susceptible, and what sorts of therapies are most effective in treating the disorder. There are many avenues being investigated to reach that goal.

Colin Firth�s portrayal of King George VI showed just one method (speech therapy) of many that have been used to treat stutters over the years. (Source: The Weinstein Company)

One effort is looking for a genetic link to the disorder. The reason: about half of the people who seek out stuttering therapy have a family history of the disorder. The familial link convinced Dennis Drayna, a geneticist at the National Institutes of Health, to screen people who stammer for possible stuttering genes.

He and his colleagues have now identified several genes that are mutated in stuttering adults. Specifically, they found that stuttering is linked to mutation of a gene called GNPTAB. Additionally, they discovered mutations in two other genes, GNPTG and NAGPA. These mutated genes are found in individuals who stutter, but not in non-stutterers.

Quite interestingly, the way to move this research forward is to introduce the mutated genes into mice to help scientists figure out what the link between gene and behavior might be. The genes are expected to disrupt a mouse's usual vocalizations. One potential obstacle: What does a stuttering mouse sound like? It�s hard to hear the sounds mice make and harder to understand them. An article in The Economist suggests that ultrasonic detectors could be used to capture the high-pitched sound of mice talking for analysis to better understand stuttering.

Another area of research discussed at the conference focuses on changes in the brain. The reason: the brain looks different in people who stutter. Using techniques such as positron emission tomography and functional magnetic resonance imaging, Lu De Nil, a speech disorder researcher at the University of Toronto, found that people who stutter often display over-activity in parts of the brain related to motor control. They also have more densely packed grey matter in the areas associated with processing and producing sounds. Evidence from other work supports this link. People who start stuttering after a stroke sometimes have lesions in these same areas of the brain, according to De Nil.

As these two research efforts and others indicate, identifying the root cause of stuttering will likely be the key to gaining a better understanding of the disorder and in determining what therapies are the best at treating it.