Scientists at the University of Alberta have collected saliva samples to create the world’s largest DNA repository of people who stutter in hopes of finding a cause and a cure for the disorder.

The DNA databank is the first if its kind and is aimed at advancing research into the genetics of stuttering, which experts say is seldom studied and poorly understood.

“The saliva DNA bank at ISTAR is the largest of its type in the world and will help address the fundamental question—what is the root genetic cause of stuttering?” said Deryk Beal, an assistant professor in the Department of Communication Sciences and Disorders in the Faculty of Rehabilitation Medicine. "The family history information we are collecting allows us to be strategic about which DNA samples we'll go to analyzing first, so there's a family that has a very strong history of stuttering, so an aunt and an uncle and a grandfather and maybe some of the grandchildren stutter, then we know that that's a family where the genetic influence runs particulary strong is strong."

Scientists say previous genetic breakthroughs have identified the cause of other disorders but that it’s much more difficult to unlock more complex “low-penetrance” disorders like stuttering because it may or may not be present even if someone carries the gene.

Researchers are looking at the whole DNA sequence to identify genetic differences in people who stutter and their family members and say at least 150 participants are needed to understand whether these genetic differences are related to stuttering.

“You need a large number of people for the true difference related to stuttering to come above the noise that that type of variability generates,” said Beal.

ISTAR started collecting saliva samples two years ago and experts say increasing their understanding of the genetic and neural causes of the condition could greatly improve the quality of life for children who suffer from stuttering.

Josh, 13, shared his saliva for the study and is practicing with a speech pathologist to keep his stuttering at bay.

His mother, Sandra, says it was an easy decision to join in on the research project.

"With no hesitation. I have a family history of stuttering and I was keen to get involved in anything we can do to shed more light on stuttering and what causes it and hopefully lead to more treatments and maybe even one day a cure," said Sandra Ukrainetz.

Additional funding is required in order to start the DNA analysis as each sample’s sequencing can cost as much as $1000. Once the funds are secure the testing will be done by a geneticist, who specializes in developmental speech-language disorders, at the Nationwide Children’s Hospital in Columbus, Ohio.

ISTAR researchers are hoping to compare the genetic analysis to MRI scans, which show structural differences in the brains of people who stutter, to determine whether differences in brain development in people who stutter are genetic or a reaction in the brain to stuttered speech.

For more information on the study and Alberta’s Institute for Stuttering Treatment and Research click HERE.