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Company plans
genetic test to predict schizophrenia
(October
2006 Issue)
By Ami Albernaz
If a test could reveal your chances for developing schizophrenia,
would you take it? The question might become more than hypothetical
as a Kentucky company is planning to have a genetic test for schizophrenia
available in two years.
The company, SureGene, a spin-off of a laboratory at the University
of Louisville, is basing its test on two genetic variations that
are evident in some schizophrenia patients. When shared by a patient
and a sibling, each variation signifies a heightened risk of developing
the illness.
Tim Ramsey, co-founder of SureGene, says the test could be taken
by adults who have passed the typical age of onset and are considering
having children. "It might be useful information to have, if they
have a family history of schizophrenia," he says. "They at least
would have the information to make an informed choice."
He imagines the test also being useful for young relatives of someone
with schizophrenia. "There's an emphasis right now on delaying onset,"
Ramsey says. "How that's going to shake out, we don't know. But
if families know the risk - if they know a child is at risk - they
can see a mental health professional and improve the outcome."
Psychologists and psychiatrists who work with schizophrenia patients
expressed skepticism about such a test, while acknowledging that
awareness of risk could have both benefits and drawbacks.
"The problem is that schizophrenia is caused by multiple genes
- maybe as many as 50 - each with a very weak effect. We don't know
yet what those genes are or the relationship and interactions between
them and the environment," says Godfrey Pearlson, M.D., director
of the Olin Neuropsychiatry Research Center at the Institute of
Living, part of Hartford Hospital in Connecticut.
He adds: "I'm amazingly skeptical of any test that purports to
give genetic risk of schizophrenia. All it could give you is a flavor
of risk based on the genetic factors known thus far."
Kim Mueser, Ph.D., a professor in the psychiatry and community
and family medicine departments at Dartmouth Medical School in Hanover,
N.H., says that unless the new test is highly accurate in revealing
a person's risk for schizophrenia, its results could be unhelpful
in a genetic counseling situation or for planning behavioral or
drug interventions during the prodromal period.
"Even the most vulnerable people [in terms of family history] don't
develop schizophrenia very often," Mueser says. If the results of
the test were not accurate, administering preventative treatment
"would very quickly become costly."
A reliable test, however, "would be tremendously useful for treatment
providers," he adds.
Pearlson, meanwhile, believes it is simply too early for knowledge
of schizophrenia risk to be of clear benefit. He gives the example
of Huntington's disease, which is fatal and for which there is no
treatment. If someone possesses a single genetic mutation, his chance
of developing the condition is 100 percent. "It doesn't help to
know that you have that genetic mutation," he says.
In the case of schizophrenia, whether or not pre-onset treatment
is helpful is up for debate, he says. Not smoking cannabis and not
taking hallucinogens are among the recommendations for people seen
to be at risk, but there is nothing specific.
Pearlson is not without optimism, though, for the benefits that
will arise from genetic testing down the road. "The wave of the
future is finding genetic tests that will give the likelihood of
developing a particular disorder: breast cancer, colon polyps or
Alzheimer's disease, for instance," he says. "The approach will
eventually pay off."
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