Depletion of Enzyme Type
Q Paraoxonase (PON-Q)
Implicated in Gulf War Syndrome
Press Release:
UT Southwestern researcher finds
genetic link for Gulf War syndrome
DALLAS - June 16, 1999 - A genetic trait can predispose people
to Gulf War syndrome, a new study has found.
In an article published in today's issue of
Toxicology and Applied
Pharmacology, a UT Southwestern Medical Center at Dallas
researcher
shows why some veterans of the Gulf War may have gotten ill from
certain chemical exposures while others did not.
Dr. Robert
Haley, UT Southwestern's chief
of epidemiology, led the
study with assistance from Dr. Bert La
Du and Scott
Billecke from
the University of Michigan Medical
School.
"One of the biggest questions about Gulf War syndrome has been
why one person got sick when the person next to him didn't," Haley
said. `"That is one of the major puzzles that made many people think
the symptoms were just due to stress.
"But now we know that there appears to be a genetic reason why
some people got sick and others didn't, and this genetic difference
links the illness to damage from certain chemicals."
Haley's study showed that people with a gene that causes them to
produce high amounts of a particular enzyme did not get sick after
exposure to certain chemicals in Operation Desert Storm, while
others who produce low amounts of the same enzyme did get sick.
The culprit gene is the one that controls production of
type Q
paraoxonase, or PON-Q, an enzyme
that allows the body to fight
off chemical toxins by destroying them. This particular enzyme is
highly specific for the chemical nerve agents sarin and soman as
well as for the common pesticide
diazinon.
In some people, the gene causes the body to produce high levels
of PON-Q, allowing their bodies to fight off toxins like nerve gas.
But in others the gene directs the production of low levels of PON-Q,
meaning a person cannot fight off even low levels of these toxic
chemicals well.
Blood levels of a genetically similar enzyme PON-R, which destroys
other chemicals more effectively than nerve agents, were no different
in the sick and well Gulf War veterans.
"In our earlier studies when we found strong statistical links between
Gulf War syndrome and veterans' reports of exposure to combinations
of chemicals like pesticides and low-level chemical nerve agents, we
predicted it might be due to a PON-Q deficiency, and now that's what
we have found," Haley said. "The sick veterans in our study have low
PON-Q levels in their blood, and the well ones have high PON-Q levels.
"We have found a genetic marker that appears to explain what made
many of these veterans sick."
In 1997, Haley and a group of other UT Southwestern researchers
published a set of three scientific papers in
The Journal of the American
Medical Association, which concluded that some veterans suffer
from brain damage caused by exposure to various combinations of
chemicals during the Gulf War.
They linked three different neurological syndromes to the use of
pesticide-containing flea collars, highly concentrated insect repellant
and pyridostigmime bromide anti-nerve gas tablets, as well as exposure
to low-level chemical nerve agents.
The current study examined the same group of men, members of the
24th Naval Mobile Construction Battalion, used in the 1997 studies.
Because these studies were conducted in a single battalion of naval
reservists, Haley and colleagues have planned a nationwide survey
to see how strongly the new neurotoxicity syndromes are associated
with low-level PON-Q enzyme levels in a random sample of Gulf
War-era veterans.
Haley, who has been researching Gulf War syndrome since 1994,
has published more than 100 scientific papers. He is an associate
professor of internal medicine with a specialty in epidemiological
research.
La Du, a professor of pharmacology and anesthesiology, is an expert
on the genetics of enzymes that destroy chemical toxins, including the
PON family of enzymes. Billecke performed the laboratory work.
The Department of Defense and the Perot Foundation provided
funding for the study.
###
EMBARGOED FOR RELEASE: 16 JUNE 1999 AT 12:00:00 ET US
Contact: Mindy Warren
melinda.warren@email.swmed.edu
214-648-3404
University of Texas Southwestern Medical Center at Dallas
Source:
http://www.eurekalert.org/releases/swmed-rfg061599.html
For educational purposes only
CNN
Coverage
Department of Defense Study: Gene Trait Could
Explain Gulf War
Syndrome
9.06 a.m. ET (1306 GMT) June 17, 1999
WASHINGTON — A genetic trait that gives some people a boost in
fighting off toxins could help explain cases of Gulf War syndrome,
researchers said Wednesday.
The gene could explain why some soldiers were afflicted with the
syndrome — which has a wide range of symptoms from flu to chronic
fatigue to asthma — the team at the University of Texas Southwestern
Medical Center in Dallas said. ...
"One of the biggest questions about Gulf War syndrome has been
why one person got sick when the person next to him didn't," said
Dr. Robert Haley, chief of epidemiology at the school,
who led
the study.
"That is one of the major puzzles that made many people think the
symptoms were just due to stress," Haley, whose research is funded
in part by the Department of Defense, added in a statement.
"But now we know that there appears to be a genetic reason why
some people got sick and others didn't, and this genetic difference
links the illness to damage from certain chemicals."
Writing in the journal Toxicology and Applied
Pharmacology,
Haley's team said a gene that controls production of an enzyme
known as type Q paraoxonase, or
PON-Q, which helps the body
destroy toxins, might be responsible.
It is highly specific for the
chemical nerve agents sarin and
soman
as well as for the common
pesticide
diazinon.
"In our earlier studies when we found strong statistical links between
Gulf War syndrome and veterans' reports of exposure to combinations
of chemicals like [organophosphate] pesticides
and low-level chemical
nerve agents, we predicted it might be due to a PON-Q deficiency,
and
now that's what we have found," Haley said.
"The sick veterans in our study have low PON-Q
levels in their blood,
and the well ones have high PON-Q levels."
Haley's group had linked three different neurological syndromes
to the use of pesticide-containing flea collars, highly concentrated
insect repellent and pills formulated with pyridostigmime bromide
to counteract the effects of nerve gas, as well as exposure to low-
level chemical nerve agents.
They now plan to test a random sample of veterans from the 1991
conflict, in which Iraqi troops were ousted from Kuwait, to see
if their theory holds true.
© Reuters Ltd. All rights reserved
Source:
http://cnn.com/HEALTH/9906/16/health.gulfwar.reut/index.html
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