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Australian scientists lead massive international study to find genetic cause of stuttering

Grant McArthur, August 18, 2019 7:00PM Herald Sun

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Without knowing what causes stuttering, health professionals can only treat the symptoms, not the cause. media_cameraWithout knowing what causes stuttering, health professionals can only treat the symptoms, not the cause.


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A massive international effort to uncover the cause of stuttering rather than treat its symptoms is being led by Australian scientists.

The researchers are hoping to gain support from 3000 Australians who stutter to help them in their ambitious quest.

It will be the biggest study of its kind and will involve scanning the genes* of more than 10,000 stutt­erers from around the world.

Researchers from The Walter and Eliza Hall Institute of Medical Research, the ­Murdoch Children’s Research Institute, QIMR Berghofer Medical Research Institute, Griffith University and the University of Melbourne hope to find common clues hidden in the DNA* of people who stutter.

Professor Angela Morgan said the project could lead to better treatments of preventive* measures for the speech disorder, which affects one in 100 Australian adults.

“At the moment there are some treatments for stuttering that work for some people some of the time, but they don’t work for everyone all of the time,” Prof Morgan said.

“That is because we are just treating the symptoms and speech … If we can get to understand the cause we might have treatments that are targeted to those underlying* mechanisms*, whether they are genetics, environment, diet-based or something else.”

Young Sam Dunworth has a stutter. Seen here with Speech pathologist Aline Murphy. 14/9/01 Pic Brent McGilvary media_cameraSam is working with speech pathologist Aline Murphy to help overcome a stutter. If researchers can find out what causes a stutter, they will better be able to help fix the problem. Picture: Brent McGilvary

Previous smaller studies have identified four genes linked to stuttering, however Prof Morgan said those ­discoveries only explained ­disorders in a handful of ­families.

She said the full underlying cause of stuttering was likely to be much more complex, involving several areas of the genome* and external triggers such as stress, diet, and other conditions.

“It is not likely that stuttering will be due to changes in a single gene. We think what is happening is changes in multiple genes or gene and environment interaction*,” Prof Morgan said.

“It is not like we are searching for one gene here, there are going to be a number of hot spots where you have certain genes or regions on a chromosome*.

“The other challenge is whether there are other environmental influences, because nobody has been able to untap that yet.”

For more information or to take part in the study visit

FILE PHOTO Queen Mother Dies At 101 media_cameraPrincess Elizabeth (now Queen Elizabeth II), her mother, Queen Elizabeth and father, King George VI, and Princess Margaret Rose wave from the balcony of Buckingham Palace on August 15, 1945. King George VI managed to make speeches and talk on the radio despite a stutter. Picture: Getty Images

Stuttering is a motor* speech disorder that affects the flow or rhythm of speech.

An individual who stutters may repeat or prolong sounds and words in their speech. They may also have repeated physical movements, such as lip tremors or eye blinking.

Stuttering does not reflect how smart or educated someone is or how well they can speak a language. It can affect people from all backgrounds, levels of education and personalities.

Stuttering typically starts between the ages of two and four years, and can persist into adulthood.

In Australia 8.5 per cent of three year olds and 11 per cent of four year olds stutter, with males two to five times more likely to be affected.

One in 100 Australian adults stutter.

Source: Murdoch Children’s Research Institute

Males are two to five times more likely to stutter than females. media_cameraMales are two to five times more likely to stutter than females.


  • genes: sequences of DNA in living things that determines heredity, or passing on biological information from a parent to a child
  • DNA: long string of molecules within genes that contains our unique genetic code
  • preventive: designed to keep something bad from happening
  • underlying: real, but not obvious
  • mechanisms: a system of parts working together
  • genome: the complete set of genes of an organism
  • interaction: how two or more things affect each other
  • chromosome: threadlike structure of DNA in living things that carries genetic information


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  1. How many Australians do the researchers need to take part in the study?
  2. What things other than genes could make it more likely for someone to stutter?
  3. Do the scientists think stuttering will be caused by one gene or many?
  4. What has stuttering got to do with how smart you are or how much you have learned to do at school?
  5. How many Australian adults stutter for each 100 people?


1. Quiz a classmate
Partner up with a classmate and test each other on the details in this news story about research into stuttering. First you must each write a set of 5 questions about the information in the article for each other. (Try to make them tricky!) Then swap questions and let your partner see if they can correctly answer the questions you wrote. Finish by swapping again to check your partner’s responses.

Time: allow 30 minutes to complete this activity
Curriculum Links: English

2. Extension
Show that you understand the meaning of the glossary words from this article by using them in new sentences unrelated to stuttering.

Time: allow 15 minutes to complete this activity
Curriculum Links: English

After reading the article, with a partner, highlight all the openers you can find in blue. Discuss if they are powerful and varied openers or not. Why do you think the journalist has used a mix of simple and power openers? Would you change any, and why?

HAVE YOUR SAY: Have you or any of your friends or family stuttered? Have you or they found anything that has helped?
No one-word answers. Use full sentences to explain your thinking. No comments will be published until approved by editors.

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