More than 2.5 million Americans have this condition arising in early childhood that can negatively impact their education, job performance, and employability well into adulthood. There is no known cure, and existing treatments are often minimally effective.
Yet for those with persistent, developmental stuttering, there is new hope, thanks to groundbreaking research led by scientists at Vanderbilt University Medical Center in Nashville, Tennessee, and Wayne State University in Detroit, Michigan.
The research findings were published in The American Journal of Human Genetics, and studies like them have the potential to identify therapeutic directions that could improve outcomes for people who stutter.
“It’s clear that in populations, stuttering is polygenic, meaning that multiple different genetic factors are contributing to and protecting people from risk,” said Below, associate professor of Medicine at VUMC.
With the help of colleagues in Ireland, England, Israel, Sweden, Australia, and throughout the United States, researchers collected blood and saliva samples for genetic studies from more than 1,800 people who stutter, including more than 250 families with three generations of stuttering.
They identified new genetic variations, or variants, associated with developmental stuttering, it was not sufficient to reveal the complexity of the condition. There were not enough people in the studies.
However, stuttering is a condition that is rarely mentioned in the medical record. People are not hospitalized for stuttering. New ways to try to capture them in hospital is needed.
Using machine learning techniques an artificial intelligence tool that used the presence of these “phenotypes” recorded in the electronic health record to predict those who were likely to stutter, even in the absence of having a direct note about their stuttering in their medical record can be developed.
Researchers demonstrated that their stuttering prediction model positively predicted the presence of stuttering more than 80% of the time.
The research also turned up a stuttering-related gene implicated in the autism-spectrum disorder, as well as genetic variants that affect the regulation of sex hormones. The latter finding may help explain why boys are more likely to stutter, and why women who stutter are more likely to recover.
Some correlations may be spurious. If the researchers establish genetic connections between stuttering and other traits such as ADHD, those findings could open up avenues for treating both conditions at the same time.