Unlocking a Medical Mystery: Stuttering

Roughly 3 million people in the United States stutter, according to the National Institutes of Health (NIH). Scientists have been looking for the cause of stuttering for thousands of years, and the condition has been considered a longtime medical mystery. Research published earlier this year in the New England Journal of Medicine, however, may have unlocked some answers.

The study, led by researchers at the National Institute on Deafness and Other Communication Disorders (NIDCD), part of the NIH, reveals three genetic mutations in the brain cells of people who stutter. The cells are located in the part of the brain that controls speech, which suggests that genes could play a big role in the disorder.

Experts say that knowing the genetic underpinnings of the disorder could unlock even more genes associated with stuttering, which could lead to more specific diagnosis and treatment.

Stuttering, also referred to as stammering, is a disruption in the normal flow of speaking. For people with the disorder, speech comes out in fits and starts, certain syllables may be prolonged or repeated, and for some, stuttering is accompanied by involuntary facial tics.

Research shows that about 60 percent of those who stutter have a family member who also stutters. The condition is most common among children, although about one percent of people carry the condition through adulthood, according to the Stuttering Foundation of America.

While previous studies have suggested that stuttering is connected to genetics, the specific genes had not been identified. This is the first study to pinpoint specific gene mutations as the potential cause of stuttering.

According to Dennis Drayna, Ph. D. a geneticist at the NIDCD and co-author of the study, the findings of the study reinforce that stuttering, at its basis, is a biological disorder, and that it is unlikely that stuttering is an emotional disorder or a social disorder.

He argues that the sooner that stuttering is recognized as a biological disorder, the sooner scientists and medical professional can get down to using that understanding to better treat the disorder.

What to Do

While there is no specific cure yet for stuttering, there are some steps you can take to support yourself.

  • Connect with other people. It can be helpful to connect with other people who stutter. Several organizations offer support groups. Along with providing encouragement, support group members may offer advice and coping tips you might not have considered.
  • Consider speech therapy. Although speech therapy has not been shown to eliminate stuttering, a speech pathologist who is knowledgeable about stuttering can almost always help adults and teens who stutter make positive changes in their communication skills. You can get a referral from the two organizations mentioned above.
  • Consider stress management practices. Feeling stressed, hurried or pressured can increase stuttering. Mind-body practices such as yoga and tai chi can help keep you calm and relaxed, and give you an overall sense of well-being.

Note: The most important rule of thumb is to stay positive and patient with yourself.  If you need additional support, contact your doctor to discuss options.


The National Stuttering Association. Web. 6 Apr. 2010. http://www.nsastutter.org/

The Stuttering Foundation. Web. 6 Apr. 2010. http://www.stuttersfa.org/

Changsoo Kang, Ph.D., Sheikh Riazuddin, Ph.D., Jennifer Mundorff, M.A., Donna Krasnewich, M.D., Ph.D., Penelope Friedman, M.D., James C. Mullikin, Ph.D., and Dennis Drayna, Ph.D. "Mutations in the Lysosomal Enzyme-Targeting Pathway and Persistent Stuttering." New England Journal of Medicine. 362:677. 25 Feb. 2010.

Mayo Clinic Staff. "Stuttering." MayoClinic.com. Web. 6 Apr. 2010. http://www.mayoclinic.com/health/stuttering/DS01027

Wenger, Jennifer. Researchers Discover First Genes for Stuttering. National Institutes of Health. 10 Feb. 2010. Web. 6 Apr. 2010. http://www.nih.gov/news/health/feb2010/nidcd-10.htm

Smith, Stephanie. "Unlocking a Medical Mystery: Stuttering." CNN. 10 Feb. 2010.  Web. 6 Apr. 2010.