March 28, 2024

Studies show genetics plays role in stuttering

DEAR DOCTOR K: My child stutters. Why does he do this? What can we do to help him?

DEAR READER: I remember the first time I met someone who stuttered. He was a playmate when I was in grade school, whose parents knew my parents. He talked about his parents a lot, but I never heard him say the words "mother" or "father." It was always "m-m-m-mother" or "f-f-f-father."

When I asked my mom about him, she explained that he was probably having “emotional problems.” That made sense to me; I couldn’t think of another reason why someone would have trouble saying such simple words.

My mom’s “diagnosis” reflected common beliefs. For a long time, stuttering was believed to be a psychological problem. But recent research suggests that stuttering has a strong biological basis, even though it may also be affected by emotions.

For example, stuttering tends to run in families. Obviously, that could be explained by emotional tensions in the family. But it also could indicate that genetic (inherited) factors play a role.

In fact, recent studies indicate that genetic factors probably play a larger role than scientists once thought. A study published in 2010 in the New England Journal of Medicine identified specific changes in genes (short sequences of genetic material) that may increase the risk of stuttering. At least one of these genes is particularly active in parts of the brain linked to motor function and emotion. Speech involves tremendous motor coordination.

There also is evidence that strong emotions and anxiety can intensify stuttering. You can’t change your child’s genetic inheritance, but you can influence his emotional state. In particular, you can help your child by doing the following:

• Be a patient, attentive listener.

• Do not finish your child’s words or sentences and do not interrupt.

• Do not pressure your child to speak to strangers or perform in public.

• Work with family members or teachers to provide a relaxed environment for your child.

Your child may benefit from working with a speech-language pathologist (SLP). SLPs use many different types of speech therapy to treat stuttering. Some of the most effective methods include:

• Modeling slower speaking.

• Teaching exercises for breath control and reducing tension on the vocal cords.

• Using a computer or other devices to give immediate feedback on how the child is doing with various strategies.

It is possible that discovering genes that cause stuttering might one day lead to specific treatments that reverse the adverse effects of these genes.

More likely, recent genetic discoveries may help identify kids who could benefit from early treatment. Such treatment of stuttering is the best hope for preventing symptoms from getting worse and becoming a long-term problem. Genetic studies could identify newborns who are at risk for stuttering and begin treating these high-risk children early in life.

Such treatment helped my childhood friend. He learned to reduce his stuttering and became a highly accomplished doctor.

Dr. Komaroff is a physician and professor at Harvard Medical School.