Some Cases of Stuttering Have Genetic Link

(February 12, 2010) - Researchers say they have discovered three gene mutations that may be responsible for at least some cases of stuttering. (Read about "Stuttering") Stuttering may be the result of a glitch in the day-to-day process by which cellular components in key regions of the brain(Read about "The Brain") are broken down and recycled, says a study in the New England Journal of Medicine. The study, led by researchers at the National Institute on Deafness and Other Communication Disorders (NIDCD), identified three genes as a source of stuttering in volunteers. Mutations in two of the genes have already been implicated in other rare metabolic disorders also involved in cell recycling, while mutations in a third, closely related, gene have now been shown to be associated for the first time with a disorder in humans.

"For hundreds of years, the cause of stuttering has remained a mystery for researchers and health care professionals alike, not to mention people who stutter and their families," said James F. Battey, Jr., M.D., Ph.D., director of the NIDCD. "This is the first study to pinpoint specific gene mutations as the potential cause of stuttering, a disorder that affects 3 million Americans, and by doing so, might lead to a dramatic expansion in our options for treatment."

Stuttering is a speech disorder in which a person repeats or prolongs sounds, syllables, or words, disrupting the normal flow of speech. It can severely hinder communication and a person's quality of life. Most children who stutter will outgrow stuttering, although many do not; roughly 1 percent of adults stutter worldwide. Current therapies for adults who stutter have focused on such strategies as reducing anxiety, regulating breathing and rate of speech, and using electronic devices to help improve fluency.

Stuttering tends to run in families, and researchers have long suspected a genetic component. (Read about "Family Health History") The researchers estimate that roughly 9 percent of people who stutter possess mutations in one of the three genes.