Psychiatr News January 4, 2008
Volume 43, Number 1, page 20
© 2008 American Psychiatric Association
Psychiatric Genetic Counseling: Don't Expect Easy Answers
Joan Arehart-Treichel
Psychiatric genetic counseling is unable to provide many definitive
answers, but once people can have their genomes sequenced at reasonable cost,
there could be greater accuracy of information provided.
Over the past 20 or so years, much has been learned about the heritability
of various psychiatric illnesses. By 2003, the human genome had been entirely
sequenced. Psychiatric geneticists are now in hot pursuit of specific genes
underlying various psychiatric disorders.
Thus it should probably come as no surprise that psychiatric genetic
counseling is getting under way as well. Jehannine Austin, Ph.D., an assistant
professor of psychiatry at the University of British Columbia, made this
announcement at the World Congress on Psychiatric Genetics in October
(Psychiatric News, November 16, 2007).
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Jehannine Austin, Ph.D.: "While we may be close to being able to
sequence a person's [entire] DNA inexpensively, we are still a long way from
being able to interpret that sequence in relation to risk for psychiatric
illness."
Credit: Jehannine Austin, Ph.D.
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Austin, it turns out, is one of the few persons in the United States and
Canada who engage in psychiatric genetic counseling. So Psychiatric
News contacted her, along with several others —Holly Peay, M.S.,
associate director of the genetic counseling training program at the National
Institutes of Health; Christine Finn, M.D., a psychiatry instructor at Harvard
Medical School and a medical geneticist; and Beth Sheidley, M.S., a
psychiatric genetic counselor at New England Medical Center —to learn
more about this burgeoning new field.
Various types of individuals seek such services, those experts said. Some
have a family history of psychiatric illness and are concerned about their
children developing it. Others have an affected child and wonder whether they
should have more children because of the risks. Still others are affected
themselves or have a spouse who is affected and worry about risk to their
children. Unaffected siblings of affected individuals are also sometimes
interested in learning what their chances of having an affected child are. And
then there is the couple who, having learned that a child they are interested
in adopting comes from a family with psychiatric illness, wants guidance on
whether to proceed with the adoption.
In many instances, the counseling that these persons undergo helps them
make informed decisions, Austin, Peay, Finn, and Sheidley indicated.
For example, Peay recently counseled a man whose wife had died from
early-onset Alzheimer's disease. He was concerned that his teenage children
might get early-onset Alzheimer's as well and wanted to have their DNA tested
for the several genes known to cause this form of the disease.
Peay told the man, however, that if he had the DNA of his children tested,
it wouldn't necessarily give him a yes or no answer, and even if it did,
"We couldn't prevent the disorder." Peay also talked with him
about his fears. The information and discussion "definitely helped
him," she said. "It was clear that he was just going to rush into
DNA testing without a clear idea of what it could achieve or what the
implications were."
A "shockingly high number" of persons who come for psychiatric
genetic counseling are afraid of having children because they have relatives
with psychiatric illness, Austin said. Yet these persons tend to overestimate
the risks, and explaining the real risks to them often eases their
anxiety.
Finn described a case that illustrates this point. A woman whose father had
schizophrenia was worried about her children getting the illness. Finn asked
her what she thought the risk was. She said 50 percent, maybe even 90 percent.
Finn told her that her own risk was only 10 percent and her children's even
less—from about 1 percent to 3 percent. This information reassured her
greatly, Finn said.
Nonetheless, only a handful of individuals are specializing in psychiatric
genetic counseling, Austin, Peay, Finn, and Sheidley reported (see How to Find
Genetic Counselors). The tools used, with a few exceptions, are pretty
basic—traditional family-history taking, not genetic testing or prenatal
diagnosis. And the challenges of conducting such counseling can be daunting,
they said.
Facing the Big Challenge
"I think the biggest challenge is the quality of information we
have," said Finn. "Right now we don't have specific tests, we
don't have definitive answers. That can be very difficult for people who are
used to yes and no answers."
Sheidley agreed. She has been offering, as part of a research protocol,
three genetic tests to parents who have a child with autism and who are afraid
of having another child with the disorder. The tests can identify several rare
causes of autism such as fragile X syndrome, but unfortunately no other genes
that could be capable of triggering autism.
Also, "most people don't understand much about genetics," said
Finn. "That is an added obstacle. And I think the media portrays
information about psychiatric genes that is much more definitive than it
really is. So people come in with unrealistic expectations."
Then there is the hurdle of whether health insurance will reimburse for
genetic counseling in general. "If the indication is related to
pregnancy or children, almost always," said Peay. "It becomes
harder for people who want to come and talk about a not-yet-conceived child.
And it definitely gets more difficult when you deal with psychiatric genetics.
I don't think the insurance companies get what the point might be."
Furthermore, as "technology moves forward, it becomes more and more
complicated to explain the meaning and limitations of genetic tests,"
Sheidley pointed out.
Indeed, "this field is incredibly dynamic and changing all the time,
and it's hard for those of us who specialize in it to keep up with it,"
Peay admitted.
Looking Beyond the Horizon
So what is coming next? Will demand for psychiatric genetic counseling
increase?
Austin and Peay both believe so. However, Sheidley is not so sure. The
reason why, she explained, is that some time ago, individuals who were at
genetic risk of Huntington's disease were asked whether they would want to be
tested for it if a genetic test were available. Most said they would. But when
such a test actually became available, many didn't want to go through with
it.
And once it becomes possible for people to have their entire genomes
sequenced at a reasonable cost—something that may happen as early as
five years from now, Ronald Davis, Ph.D., director of the Stanford Genome
Technology Center, reported at the World Congress on Psychiatric Genetics in
October—will it improve the accuracy of psychiatric genetic counseling?
"Absolutely!" Peay said.
Finn, however, is only reasonably sanguine. "I hope that we can be
more precise, more individual in our risk estimation."
And Austin is even less confident. "While we may be close to being
able to sequence a person's [entire] DNA inexpensively, we are still a long
way from being able to interpret that sequence in relation to risk for
psychiatric illness, or indeed many other illnesses. So even if we could
sequence the DNA cheaply, it would not yet be able to tell us much about that
person's risk for psychiatric illness." 
Related Article:
-
How to Find Genetic Counselors
Psychiatr News 2008 43: 20.
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