Austin Sanday is an active, happy nine-year-old from Queensland, who enjoys video games, soccer and playing with his dog.

"I like to play with my dog, Rosie. I like to go bike riding with my mum, play with my friends in the street and have friends over to swim in my pool," he said.

But he feels frustrated when he cannot get his words out and wishes more people knew about and understood stuttering.

Austin has a few ideas of what he would like to be when he grows up and is currently deciding between 'a lawyer, a comedian or a software engineer.'

"I started stuttering when I was three years old. I didn't think any more about it until I was six," he said.

"I get really frustrated and angry when I can't get the words out. It takes so long to say things sometimes.

"I wish other people knew that stuttering is a disorder that you can't help. I wish more people knew about it and understood how it feels to not be able to get your words out."

Austin is taking part in The NHMRC funded 'Genetics of Stuttering Study.'

MCRI's lead researcher, speech pathologist Professor Angela Morgan, said the Australian-led international study aimed to pinpoint the genes that cause stuttering. Researchers suspect people who stutter have a slight 'glitch' in the brain connections for speech but as many as 70 per cent of people with stuttering report a family history.

"Despite records of stuttering going back over 400 years, we still have little idea of what causes stuttering," Angela said. "While many current therapies are effective for most people, there are some for whom therapies do not work.

"This is partly because therapies are based on treating surface symptoms rather than the cause. If we can work out the cause - which data suggests is genetic - we can tailor therapies such as drug therapies targeting perturbed gene pathways."

Stuttering affects one in 10 pre-school children but 80 per cent of cases resolve with therapy or by themselves. About one in 100 adults live with stuttering.

"We have recruited around 2000 people to date, but need another 1000 people living in Australia," Angela said. 

The study could help transform future research and treatment. 

People aged five and over, who stutter or have a history of stuttering and wish to volunteer for the study or learn more can head to or email  . Participants complete a 10-minute survey, and we will send a saliva spit kit to collect your DNA for genetic analysis.