One in a 100 Australian adults is affected by stuttering, but the cause of the speech disorder is unknown.
A global study involving Australian experts is searching for the genes believed to cause stuttering.
Professor Angela Morgan from the Murdoch Children’s Research Institute says there is already evidence genetics plays a role.
"So at the moment, we know that 70 per cent of individuals who experience stuttering they do have a family history of stuttering. We also know that there have been four single genes identified to be associated with stuttering," Professor Morgan said.
Boys are up to five times more likely to be affected by stuttering than girls.
"So stuttering actually occurs in 1 in 10 children who are of preschool age. But we know around 80 per cent of children actually recover, either with or without treatment. And the remainder can then go on to have a persistent stutter," Professor Morgan said.
Chief study investigator - Professor Melanie Bahlo from The Walter and Eliza Hall Institute of Medical Research - says better understanding of what causes the speech disorder could lead to improved treatments.
Researchers want to recruit 3,000 Australians aged seven-years and over with a history of stuttering.
To take part in the study, volunteers need to complete an online survey, record a sample of their speech, and supply a saliva sample for D-N-A analysis.
So far almost 600 people have signed up.
