Curtin University researchers are on the hunt for the genes which may be responsible for stuttering, believing genetics, rather than environmental or behavioural factors, may trigger the disorder which affects approximately 11 per cent of Australia’s population.

Associate Professor Janet Beilby, from Curtin’s School of Psychology and Speech Pathology, said the hunt to identify the genes which may be responsible for the condition would see researchers examine saliva samples from 4,000 participants over the next two years.

“Stuttering is a problem in the ongoing rhythm of speech where a person knows exactly what they want to say but involuntarily loses control of their speech muscle patterns just as they are about to speak,” Associate Professor Beilby said.

“It manifests itself as either repetitive speech or a dragging or cessation of speech but individuals are perfectly eloquent if they are singing, whispering or talking in time to a beat.

“We still don’t know what causes stuttering but the overall consensus is that it is a complex interplay between a multitude of factors.

“What we are doing now is hunting for the genetic markers for stuttering – we haven’t found them yet but the hunt is proving very interesting because it is uncovering a lot of unique findings, one of which is a strong penetrance in Western Australian families.”

The study builds upon Associate Professor Beilby’s 2014 research project on stuttering.

“In England or Europe you may find only a couple of people across a few generations of the same family who stutter but in WA we are finding an increased penetrance with a whole generation of young people with these particular symptoms,” Associate Professor Beilby said.

“For this new study, we are seeking participants who stutter but are especially keen to collect samples from multiple generations of people who stutter in the same family – their stories and data will go a long way to potentially identifying the gene responsible for the debilitating condition.”

The ultimate aim of the study is to identify which genes are responsible for stuttering so it can be screened for and children identified at risk can be monitored and offered early intervention as needed. This would prevent the ‘watch and wait’ approach currently utilised and which often results in the disorder being strengthened over time until it is too intractable to treat.

“People who stutter start to do so between two and three years of age when they are beginning to master adult speech development,” Associate Professor Beilby said.

“This is the ideal age to nip it in the bud so if we can stop the child practising it, then we can set them up successfully for life.

“Within the family cohorts we already have, there is a unique family whereby 15 members across four generations all stutter – imagine the impact this research could have on the lives of their future children.”

The research, which is funded by an AUD$391,000 grant from America’s National Institute of Health, is being conducted at Curtin University Stuttering Treatment Clinic in collaboration with Dr Shelly Jo Kraft from Wayne State University, Detroit.

For more information, email Dr Janet Beilby on j.beilby@curtin.edu.au or visit the Curtin Stuttering Clinic website at http://healthsciences.curtin.edu.au/schools-and-departments/psychology-and-speech-pathology/clinical-services/stuttering-clinic/