CONTACT: DAVE PEDERSEN
283 Medical Laboratories
Iowa City IA 52242
(319) 335-8032; fax (319) 335-8034
UI researchers studying genetics of panic disorder
IOWA CITY, Iowa -- Researchers at the University of Iowa College of
Medicine are interested in talking to families whose members experience
panic disorder -- repeated, unprovoked bouts of anxiety or terror that
occur for no apparent reason.
The researchers hope that by studying family members with this condition,
they will move closer toward identifying the gene or group of genes responsible
for panic disorder.
"When something frightens us, it's normal to feel panicky or anxious.
But what makes panic disorder a disease is that people with this condition
suffer panic attacks when there is no reason for them to be frightened,"
says Dr. Raymond Crowe, UI professor of psychiatry. "This is a disorder
that often runs in families, which is why we are interested in its genetic
Crowe recently received a three-year, $600,000 grant from the National
Institute of Mental Health to continue genetic linkage studies of families
with panic disorder, a project he and his colleagues have been working
on for 10 years. So far, UI researchers have studied 20 families -- about
300 people -- who have three or more members with panic disorder.
Panic disorder is one of several types of anxiety disorders, along with
certain phobias, obsessive-compulsive disorder and post-traumatic stress
disorder. Physical symptoms -- chest pain, dizziness, shortness of breath
and sweating -- can often accompany panic attacks. It affects as many as
three percent of the population and affects women more than twice as often
Agoraphobia, or the fear of leaving the safety of one's home and being
out in public, can sometimes occur because of panic disorder, Crowe says.
"We've talked to people who have become agoraphobic because they had
a panic attack in a public place. The experience made them fearful of returning
to these types of situations," he says.
Several medical and behavioral treatments are available for panic disorder.
Various antidepressants have been effective for panic disorder, and support
groups also seem to help people with agoraphobia. But as Crowe notes, researchers
have yet to find the biological basis for anxiety disorders. This is where
genetics studies come in.
Crowe and his colleagues conduct interviews and collect small blood
samples from families who have three or more members with panic disorder.
The interviews, which last about an hour and are done at the families'
homes, collect information about each person's panic attacks and the conditions
that cause them. The interviews help confirm which persons in a family
have the condition and which do not.
DNA is then extracted from the blood samples in order to study each
person's genetic makeup. Genome markers --similar to mile markers on a
road or map -- enable researchers to identify similarities or differences
in people's genetic sequencing. "We look for whether all of the people
in a family with panic disorder share one of those markers," Crowe
says. "We want to see if people with the disorder inherit the marker
and also if people who don't have the disorder do not inherit it."
If they do, and this kind of sharing becomes apparent in family after
family, it suggests the shared marker is close to a gene that predisposes
individuals to the disorder. "We use the markers as tools to narrow
it down. Then we will look for actual genes in that area and see if we
can find a mutation in one of them that might be the cause," Crowe
By identifying the disorder-causing gene, researchers may gain clues
as to what parts of the brain, or which chemical messengers to the brain,
are affected. This may ultimately lead to better, targeted treatments.
"We might find a deficiency in a chemical or perhaps that the chemical
is present, but inactive," Crowe says. "The more people and families
we are able to study, the more it helps. Families with four, five or six
members with panic disorder are really valuable to us."
Families with three or more members experiencing panic disorder are
invited to take part in the UI study. For more information, call (319)