NEW DELHI– The causes of stuttering, a long-standing mystery in speech pathology, may now be closer to understanding. A team of U.S. researchers has found compelling genetic evidence linking the disorder to specific genes, potentially paving the way for earlier diagnosis and improved therapies.
In a study published Monday in Nature Genetics, scientists identified 48 genes and 57 distinct genomic loci associated with stuttering, based on the genetic data of more than one million individuals. The findings shed light on one of the most common fluency disorders in the world—affecting more than 400 million people globally—yet one that remains poorly understood.
Stuttering is characterized by repeated syllables or words, prolonged sounds, and pauses between words. Despite its prevalence, the disorder has historically lacked clear biological explanations, often giving rise to stigma and misconceptions.
“No one really understands why someone stutters; it has been a complete mystery,” said Jennifer (Piper) Below, Professor of Medicine at Vanderbilt University Medical Center. “And that’s true for most speech and language pathologies. 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.”
Below emphasized the importance of identifying risk factors early in life to ensure timely and effective intervention. “We need to understand risk factors for speech and language traits so that we can identify kids early and get appropriate care for those that want it.”
Stuttering has been shown to negatively affect social and educational development. Children who stutter often experience increased bullying, reduced classroom participation, and long-term impacts on mental health. In adulthood, the condition can influence job opportunities, professional perception, and overall well-being.
“Rather than being caused by personal or familial failings or intelligence, our study shows that stuttering is influenced by our genes,” Below said.
Developmental stuttering typically begins in children between ages 2 and 5. About 80 percent of cases resolve spontaneously, with or without speech therapy. However, stuttering tends to persist more often in males than females, with adult prevalence showing a 4:1 male-to-female ratio.
To investigate further, researchers analyzed eight sex- and ancestry-specific population groups, followed by comprehensive meta-analyses. They identified 57 genomic regions tied to stuttering risk, mapped across 48 genes. Notably, the genetic risk profiles differed between males and females, possibly helping to explain why stuttering persists in some individuals but not others. (Source: IANS)
