WEDNESDAY, Sept. 27 (HealthDay News) -- Certain genes may raise the risk for a compulsive hair-pulling disorder known as trichotillomania, U.S. researchers report.

This impulse-control disorder affects 3 percent to 5 percent of the population. People with trichotillomania have noticeable hair loss or bald patches. The condition often accompanies other psychiatric disorders, such as anxiety, depression, obsessive-compulsive disorder or Tourette syndrome.

This study included 44 families with one or more members with trichotillomania. Researchers at Duke University Medical Center, in Durham, N.C., found that some people with trichotillomania had two mutations in the SLITRK1 gene. These mutations were not found in family members who did not have the disorder.

The SLITRK1 gene plays a role in the formation of connections among brain cells (neurons). Mutations in the gene may cause neurons to develop faulty connections that result in trichotillomania, the scientists said.

But they also stressed that SLITRK1 gene mutations probably account for only a small percentage of trichotillomania cases.

The findings were to be published in the October issue of Molecular Psychiatry.

Currently, there is no specific treatment for trichotillomania. It's sometimes successfully managed with drugs designed to treat anxiety disorders and depression.

More information

The U.S. National Library of Medicine has more about trichotillomania.