Study finds first genes linked to stuttering
NEW YORK - Why people stutter has long been a medical mystery, with the condition attributed over the years to emotional problems, overbearing parents, and browbeating teachers. Now, for the first time, scientists have found genes that could explain some cases of stuttering.
“In terms of mythbusters, this is really an important step forward,’’ said Jane Fraser, president of the Stuttering Foundation of America, based in Tennessee.
Researchers taking part in a government-funded study discovered mutations in three genes that appear to cause the speech problem in some people. Stuttering tends to run in families, and previous research suggested a genetic connection. But until now, researchers had not been able to pinpoint any culprit genes.
Geneticist Dennis Drayna, senior author of the study, released yesterday by the New England Journal of Medicine, said he hopes it helps convince doubters that stuttering “is almost certainly a biological problem.’’
The research also points to a possible enzyme treatment for stuttering.
Without a known cause, stuttering has been attributed to such things as nervousness, lack of intelligence, stress, or bad parenting. Stutterers were told it was all in their heads. Fraser said parents contact her organization worried they have done something to cause their children’s stuttering. Were they too strict? Too attentive? Didn’t pay enough attention? The gene discovery should lift that guilt, she said.
Stuttering usually starts in children as they are learning to talk. Most youngsters lose their stutter as their brain develops. For some, it persists. An estimated 3 million Americans stutter. Treatments includes speech therapy and electronic devices.
“This is a very difficult disorder to study,’’ said Drayna, who is a researcher at the National Institute on Deafness and Other Communication Disorders. “You can’t study it in cells in a dish. You can’t study it in a test tube. You can only study it in awake humans.’’
To find the genes, Drayna and others first looked at a large, inbred Pakistani family with many members who stuttered, and discovered a mutation on a particular chromosome. Then they found the same mutation and two other mutated genes in a group of nearly 400 other people from Pakistan, the United States, and England who stutter.
“The task of connecting the dots between genes and stuttering is just beginning,’’ Simon E. Fisher of England’s Oxford University wrote in an accompanying editorial.