What Causes Stuttering? A Large DNA Analysis Study Offers New Clues, Uncovering Links to 48 Genes

Scientists analyzed data from more than one million users of 23andMe and found associations between certain genes and stuttering

Sara Hashemi | Daily Correspondent

September 25, 2025

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Stuttering is a common speech condition that affects more than 70 million people across the world. But despite its prevalence, its cause is not well understood by scientists. Now, a recent study sheds light on genes linked to stuttering.

“No one really understands why someone stutters; it has been a complete mystery. And that’s true for most speech and language pathologies,” explains Jennifer Below, a geneticist at Vanderbilt University Medical Center, in a statement. “They are profoundly understudied because they don’t put people in the hospital, but they can have enormous consequences on people’s quality of life.”

To learn more about the condition, Below and her colleagues examined the genetic profiles of thousands of users of 23andMe, a DNA genetic testing company. The team looked at data from 99,776 users who self-reported as having had a stammer or stutter, as well as data from 1,023,243 control users who didn’t. The researchers found 57 genetic regions that mapped to 48 genes linked to stuttering. Their results were published in the journal Nature Genetics in July.

'Life-changing' genetic link offers hope for millions who stutter

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The strongest associated gene in males was VRK2, which has also been associated with the ability to clap on beat and language decline in people with Alzheimer’s disease. The study also found genetic similarities between stuttering and autism, depression and musicality.

Loryn McGill, a speech-language pathologist at the University of Southern California who was not involved in the work, tells Nazeefa Ahmed at Science that the study confirms stuttering is indeed a neurological condition, and not a behavioral or emotional problem. She adds that she hopes the study helps inform doctors that stuttering can run in families.

The research does have a few limitations. For one, the ratio of women to men in the study did not match that of people who actually stutter—men are more likely than women to stutter, but the study had a higher number of female participants. The researchers also did not have enough participants with Asian and African ancestry to draw conclusions about those groups, reports Science.

Many people who stutter report bullying and experience heightened levels of self-doubt, insecurity and hopelessness. Stuttering can also negatively impact employability, pay and perceived job performance. Understanding that the condition is genetic could ease some of that social stigma, the authors say.

Additionally, finding genetic components of stuttering might allow early intervention into speech programs. “Based on what we’ve found in this research, we will be able to take a DNA sample and predict if the individual is likely to stutter or not,” says study co-author Janet Beilby, a speech pathologist at Australia’s Curtin University, to the Australian Broadcasting Corporation’s Lily Kristanto.

Dillon Pruett, a study co-author who stutters himself, had a lot of questions about the condition growing up, but didn’t find many answers. “Our study found that there are many genes that ultimately contribute to stuttering risk, and we hope to use this knowledge to dispel stigma related to stuttering and also to hopefully develop new therapeutic approaches in the future,” he says in a statement.

“We want to get out the message that stuttering is a genetic trait that is not someone’s fault, to help change public perception and help dispel some of the internalized feelings of wrongdoing,” Below adds to Science.

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Sara Hashemi is a science writer and fact-checker currently based in New York City. Her work has appeared in Sierra, The Body, Maisonneuve magazine and more.