New DNA bank collecting samples to understand causes of stuttering

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Sandra Ukrainetz can never predict when her son Josh will stutter. Sometimes, the 13-year-old Calgary boy will speak fluidly for months without incident. Other times, he can barely have a conversation without stammering.

Ukrainetz has worked hard to try to identify triggers for his speech impediment, which emerged before the age of 3. But, so far, it's been to no avail.

She's hopeful, however, that a new DNA bank, launching Wednesday at the University of Alberta's Institute for Stuttering Treatment and Research, will help shed light on the mysterious disorder, which affects about 1 per cent of the population at some point in their life. Josh is among more than 150 clients of the institute who, along with their families, have provided saliva samples to the DNA bank, which researchers will use to study the genetic factors involved in stuttering.

The idea that stuttering runs in families has been around for more than 50 years, says lead researcher Dr. Deryk Beal, the institute's executive director. Some research has suggested male children of women who stutter tend to be at highest risk for developing the disorder. And males are much more likely to stutter than females. Yet few large-scale studies have examined the underlying genetics of the disorder.

Beal explains that the long-term goal of his project is to combine the participants' genetic data from the DNA bank with neuroimaging to understand how their genes contribute to their brain development. Once they're able to understand the root causes of stuttering, researchers can start looking for molecular pathways that are involved in brain development, which eventually may lead to better treatment. Currently, stuttering is treated with speech therapy, which involves training an individual to use skills that promote fluid speech, and by addressing the social and emotional effects of living with the disorder. There is no cure.

"Stuttering has been a mystery for hundreds, if not thousands of years," Beal says. But to really make strides in how it's treated, he says, scientists will need to understand the genetic and neural mechanisms.

So far, neuroimaging has shown that in people who stutter, the order of brain signals involved in speech is reversed. In fluid speakers, the areas of the brain involved in planning what to say are activated first, and the areas related to executing speech are activated second. But generally in those who stutter, the areas related to execution are activated before the planning areas.

Research has also shown differences in the brain structure of people who stutter, specifically in a region of the brain related to speech difficulties.

For her part, Ukrainetz points out there are still many myths and misconceptions about stuttering, such as the notion that it's caused by a traumatic event, or that people who stutter have learning disabilities. Even though she notes her son's stuttering does not hold him back socially or emotionally, it can be heartbreaking for her to see him struggle to communicate.

"That's why I want to participate in this research. Just anything I can do to help shed light on it or help maybe find a cure, we'd do anything."