The disorder affects between 3 percent and 5 percent of the population and is considered an impulse control disorder. Patients with trichotillomania have noticeable hair loss or patches of baldness, but they often mask their habit. As a result, the disorder often goes undiagnosed and untreated, said researchers.
The relatively unknown disorder is often accompanied by other psychiatric conditions, such as anxiety, depression, obsessive compulsive disorder or Tourette syndrome, which are better known than the hair-pulling behavior.
The Duke team found two mutations in a gene called SLITKR1 that were implicated in trichotillomania patients. The mutations account for only a small percentage of trichotillomania cases, said the scientists.
However, their findings are significant because they validate a biological basis for mental illnesses. Such illnesses have long been blamed on a person's upbringing or life experiences, said lead study investigator Stephan Züchner, M.D., assistant professor of psychiatry and researcher at the Duke Center for Human Genetics.
"Society still holds negative perceptions about psychiatric conditions such as trichotillomania. But, if we can show they have a genetic origin, we can improve diagnosis, develop new therapies and reduce the stereotypes associated with mental illness," Züchner said.
Currently, there is no specific treatment for trichotillomania, although it is sometimes successfully managed with drugs used for depression and anxiety disorders.
Results of this study will appear in the October 2006 issue of the journal Molecular Psychiatry. The research was self-funded through Duke University.
The Duke scientists studied 44 families with one or more members who had trichotillomania. The researchers studied SLITRK1 because it was linked last year to a related impulse-control disorder called Tourette syndrome, which causes repetitive behaviors such as blinking, throat-clearing or shouting obscenities. The parent of one Tourette patient carried the SLITRK1 mutation but displayed only symptoms of trichotillomania, not Tourette.
The Duke team further studied SLITRK1 and found two mutations in the SLITRK1 gene among some individuals with trichotillomania but not in their unaffected family members. Mutations are changes in the structure of a gene that alter how the gene behaves. The researchers estimate that the SLITRK1 mutations account for 5 percent of trichotillomania cases.
The SLITRK1 gene is involved in forming connections among neurons, or brain cells. The researchers hypothesize that the two mutations in SLITRK1 cause neurons to develop faulty connections and that this faulty "wiring" produces the urge to pull one's hair.
While SLITRK1 is the first gene linked with trichotillomania, numerous other genes likely contribute to this disorder and other psychiatric conditions, said senior study investigator Allison Ashley-Koch, Ph.D., assistant professor of medical genetics and researcher in the Duke Center for Human Genetics.
"The SLITRK1 gene could be among many other genes that are likely interact with each other and environmental factors to trigger trichotillomania and other psychiatric conditions," Ashley-Koch said. "Such discoveries could open the door for genetic testing, which is completely unheard of in the field of psychiatry."
Compared with neurological diseases, the identification of genes which underlie psychiatric disorders have only just begun, she said. Few other examples exist where a specific gene is known to trigger a psychiatric condition, although it is generally accepted that genetic factors play an important role.
Psychiatric illnesses are widespread, affecting one in four Americans, according to the National Institutes of Mental Health. They are the leading cause of disability for Americans between the ages of 15 and 44. The most common disorders are depression and anxiety disorders, such as panic disorder, obsessive compulsive disorder and social phobia.
October 1-8, 2006, is National Trichotrillomania Awareness Week.
Other researchers involved in this study were Michael L. Cuccaro, Khanh Nhat Tran-Viet, Heidi Cope, Ranga R. Krishnan and Margaret A. Pericak-Vance of Duke and Harry H. Wright of the University of South Carolina.
Marla Vacek Broadfoot | EurekAlert!
The birth of a new protein
20.10.2017 | University of Arizona
Building New Moss Factories
20.10.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
20.10.2017 | Information Technology
20.10.2017 | Materials Sciences
20.10.2017 | Interdisciplinary Research