by Christina Medvescek
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For Rob and Sharla
Roozeboom, getting a
new diagnosis helped in family planning. |
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Sometimes the question facing people affected by a neuromuscular disease
isn't "What kind of test should I have?" but "Should
I have a test?"
Finding the correct diagnosis is a straightforward scientific process
requiring technological tools and medical detective work (see "Rounding
Up the Usual Suspects"). But like opening Pandora's box, receiving
a diagnosis is anything but straightforward. A diagnosis, especially
of a genetic disease, can carry an emotional punch that sends patient
and far-flung relations reeling.
Now that people can be more easily and exactly tested for specific
genetic diseases, the question "Do I want to know?" becomes
acute. Below are some common issues confronting individuals and families
today.
Q: Is it worth the expense and hassle
to undertake new testing to confirm or refute an earlier diagnosis?
A: Yes — and no. In some cases, there are clear advantages to
positively confirming your diagnosis; in other cases it won't make any
difference at all.
The advantages are found in identifying inheritance patterns, gaining
knowledge about the course of the disease and being able to participate
in ongoing research.
Different neuromuscular diseases have different inheritance patterns;
even within a single disease, such as Charcot-Marie-Tooth disease (CMT),
there are genetic variations, says Karen Krajewski, certified genetic
counselor and assistant professor of neurology at Wayne State University
in Detroit.
If you have a disease with several genetic variations, and if you're
hoping to participate in clinical research trials, a precise genetic
diagnosis is essential. Knowing the exact mutation allows you to participate
in clinical trials aimed at that form of the disease.
Knowing exactly what you have also can be informative when you're planning
for parenthood. Rob Roozeboom of Sheldon, Iowa, received a diagnosis
of Becker muscular dystrophy (BMD) when he was 5 years old. But in his
early 20s — married and hoping to have children — MDA doctors
began to suspect he had something else and gave him a DNA blood test
for BMD. It came back negative. Based on the test, his disease progression
and family history, Roozeboom's diagnosis was changed to limb-girdle
muscular dystrophy (LGMD), changing the inheritance pattern for his
future children.
BMD is X-linked, meaning all of Roozeboom's daughters would be carriers
and would be at risk of having boys with BMD. But Roozeboom's form of
LGMD apparently is autosomal recessive, meaning both parents need to
be carriers in order for the disease to be manifested in a child. Although
all of Roozeboom's children — boys and girls — will be LGMD
carriers, the risk of the disease actually showing up in future generations
of Roozebooms is less than with BMD.
"Being diagnosed with limb-girdle kind of allowed us to still
pursue our dreams of children," Roozeboom says. On Nov. 4, the
Roozebooms had a baby boy, Jager, who is doing well.
Even if parenthood isn't an issue, a genetic diagnosis can be useful
for other family members. "In families where it's not clear if
other people are affected, once you establish a genetic diagnosis, those
individuals can be tested so that you know definitely," Krajewski
explains.
Another advantage to knowing the genetic diagnosis is that some neuromuscular
diseases carry increased risks for other disorders, such as a bad reaction
to anesthesia, heart problems or diabetes. An exact diagnosis may help
you prevent problems down the line or direct your doctor toward the
most appropriate treatment.
But in general, if you have a diagnosis that seems to fit, aren't worried
about inheritance patterns and don't plan to participate in a clinical
trial, there's no real advantage at this time to confirming a diagnosis
by genetic test. In fact, sometimes test results can be vague and ambiguous,
leading to more confusion instead of less, Krajewski says (see "DNA
Evidence").
And some insurance companies balk at paying for the expensive tests,
especially if you get more than one. Genetic tests can range from several
hundred to several thousand dollars each.
The decision to undergo further testing comes down to personal preference,
Krajewski says. "For a lot of patients it [a precise diagnosis]
doesn't change things for them. And for others, even though it might
not change treatment, there is a feeling of control they get from knowing
specifically what's happening, even if they can't do anything about
it."
Q: Should children, siblings or other
relatives who aren't showing any disease symptoms be tested anyway to
see if they're carriers, or might develop the disease later?
A: In general, the medical establishment frowns on testing children
for late-onset disease or carrier status if the children aren't showing
any disease symptoms and if there's no medical or psychological benefit
to knowing at a young age.
"There is no reason for a 6-year-old girl to know about her chances
of having a child with a disability — that's her choice to make
when she gets older," says Cheryl Scacheri, a senior genetic counselor
with GeneDx in Gaithersburg, Md. "You [her parents] might make
a different decision when the child becomes sexually active."
But if a family is adamant about testing a child, and they believe
a test won't cause any medical or psychosocial harm, then health care
providers should "respect the decision," say both the American
Society of Human Genetics (ASHG) and American College of Medical Genetics
(ACMG). Psychosocial issues include anxiety, negative self-image, uncertainty,
social stigma and the impact of knowing on decisions about reproduction,
education, career, insurance and lifestyle.
(To see the ASHG/ACMG policy paper, "Ethical, Legal and Psychosocial
Implications of Genetic Testing in Children and Adolescents," go
to www.acmg.net/resources/policies/pol-018.asp.)
"Fred,"
feels strongly that his teen-age son — who isn't showing symptoms
— shouldn't be tested. Fred, 53, recently learned that he has
myotonic muscular dystrophy type 2 and is very concerned about psychosocial
issues for his son.
"If he does have it, it probably won't begin to show up until his
40s. I don't want him to be worried at this age, when the disease might
not even show up," he explains. "Every girl he thought of
marrying he'd have to tell. I don't want to do that to him. I would
rather he leads a normal life. If he finds out when he's almost 50,
that's different. They may have treatment for it later."
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| Pete Siegel's son, Virgil, got a positive
CMT test result at age 4. |
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On the other hand, psychosocial issues are the main reason Pete Siegel,
35, of Billings, Mont., wanted his 4-year-old son, Virgil, tested for
CMT, although the boy didn't show any symptoms at the time. His son,
now 12, tested positive for the disease.
Siegel's father and a few relatives have CMT, but Siegel never was
told about it while growing up. He says he battled self-esteem issues
because "I couldn't understand why I wasn't as fast and strong
as everyone else. I thought it was just me." Siegel believes his
father kept quiet about CMT out of fear, denial and maybe a little guilt.
If he'd known, Siegel says, he would have made different career decisions
and gone to college. Instead he enlisted in the U.S. Marine Corps and
then couldn't make it through boot camp. "I just made some poor
choices in my life that if I'd known I had muscular dystrophy, I wouldn't
have made."
When a doctor gave him the diagnosis at age 19, he felt betrayed and
angry. "I felt they kept a secret from me that affected me. I could
have been told when I was 10 or 12."
Siegel is open with Virgil, who already has CMT symptoms. "Whenever
he asks questions, I tell him what I know. I don't sugarcoat it. He
needs all the information he asks for." An avid hunter, fisherman
and stock car racer, Siegel also encourages his son "not to let
this be an excuse not to do something."
Lately, Siegel has been urging his sisters to have their children tested
because "I see the signs in their legs. It's as plain as black
and white. For me, knowledge is power. I believe that in my heart."
Q: What tests are available to see if
an unborn child has a neuromuscular disease?
A: We live in a brave new world when it comes to prenatal diagnosis.
It's now not only possible to tell if your unborn child has muscular
dystrophy, but to ensure from the beginning of the pregnancy that he
or she doesn't.
A definite "yes or no" diagnosis can be made via chorionic
villus sampling (CVS) at 11 to 12 weeks gestation, or amniocentesis at 15 to 19 weeks. In CVS, cells from the developing placenta are examined;
in amniocentesis some of the amniotic fluid surrounding the baby is
drawn out and tested. Both tests very slightly increase the risk of
miscarriage.
If the fetus is affected, a couple can decide whether to continue the
pregnancy, knowing better how to prepare emotionally, financially and
domestically for the new child.
With preimplantation genetic diagnosis (PGD), parents can know
for sure that their baby doesn't have a particular genetic disease before
pregnancy begins. PGD combines the fertility technology of in vitro
fertilization with genetic testing.
Eggs are collected from the mother and fertilized in the lab with the
father's sperm, and any resulting embryos are tested for the suspected
genetic disease when they've grown to the eight-cell stage. Unaffected
embryos then are implanted in the mother's womb. Pregnancy success rates
range from 20 percent to 50 percent, with younger mothers having the
best chances. PGD doesn't guarantee that a baby won't have other birth
defects or difficulties.
For obvious reasons, prenatal diagnosis is a white-hot issue among
parents and members of the disability community. It involves closely
held attitudes toward abortion, the beginning of life, God, fate, disability,
social responsibility and the definition of "a good life."
Deciding whether to test an unborn child can be agonizing, but it's
a couple's personal choice.
Robin Guyton, 39, of Bossier City, La., has a family history of Duchenne
muscular dystrophy (DMD), including a 36-year-old brother affected by
it. After bearing two daughters (now in their 20s), Robin decided to
have amniocentesis with her last two pregnancies — a gut-wrenching
but ultimately valuable experience. Her third child, Benjamin (BJ),
has DMD but her son Taylor, born in October 2001, doesn't.
"With my first two pregnancies I was young. I didn't worry [about
having a child with DMD], and there were no specific tests available
anyway," she recounts. While pregnant with BJ she underwent amniocentesis
but, after learning the baby was a boy, she decided she didn't want
to know the results of the test for DMD.
"I thought, "If he has it, what will I do?" I know it's
a horrible disease but my brother has had a productive life. I just
couldn't throw away another human being. I went through a hundred different
emotions. The lab people looked at me like I was stupid for not wanting
to know, but it's a private thing."
But when she got pregnant again with Taylor, she decided she needed
to know. "I know how special BJ is," she said. "I just
wanted to be prepared in case there was a problem and to prepare the
rest of the family. I felt very protective toward the [unborn] child
and kind of isolated, like it was just us against the world."
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| Robin Guyton, center, had prenatal
testing with her two youngest children. Son BJ, right, has Duchenne
MD, but younger son Taylor doesn't. |
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Guyton and her husband, Robert, agreed they wouldn't terminate the
pregnancy in case of DMD. The tests came back negative.
Guyton recommends prenatal testing to others with a family history
of DMD. "This disease doesn't just affect one person, it affects
everybody in the family. You need to prepare people and prepare yourself."
Q: Isn't there a downside to genetic testing?
Could the results of a genetic test lead to discrimination by an employer
or insurance company?
A: If you already have a documented medical diagnosis of a neuromuscular
disease, having a genetic test to confirm the diagnosis won't make you
more vulnerable to discrimination. If you have no symptoms and no diagnosis,
some safeguards are in place to help protect against possible employment
or insurance discrimination based on results of a genetic test.
The first, of course, is the Americans with Disabilities Act (ADA),
which prohibits discrimination in employment on the basis of disability.
In fact, having a definitive diagnosis can work in your favor, says
genetic counselor Karen Krajewski, by documenting that you're covered
under the act.
In 2001, the Equal Employment Opportunity Commission (EEOC), which
enforces the ADA, shut down an apparent attempt at genetic discrimination
by the Burlington Northern Santa Fe Railroad. The railroad was taking
blood samples from employees who had filed workmen's compensation claims
for carpal tunnel syndrome, allegedly looking for a genetic predisposition
toward that disorder. Those who refused to give blood samples were threatened
with dismissal. The EEOC ruled that, "Any test which purports to
predict future disabilities, whether or not it is accurate, is unlikely
to be relevant to the employee's present ability to perform his or her
job."
Limited safeguards exist against insurance discrimination. The Health
Insurance Portability and Accountability Act of 1996 (HIPAA) says:
Genetic information may not be used to deny or limit coverage in the
group (as opposed to individual) insurance market.
Genetic information is excluded from being considered as a preexisting
condition.
In certain cases, federal protections against genetic discrimination
cover people changing insurance coverage, such as in a divorce or a
job change (providing certain standards are met).
Procedures, standards and security technology have been put in place
to protect private personal health information, including the results
of genetic testing, from being electronically stolen or released without
the person's authorization.
Some state insurance laws offer even more protection than HIPAA; check
with your state insurance commission to find out. For more information
on HIPAA, visit cms.hhs.gov/hipaa or call the Centers for Medicare and Medicaid Services (CMS) at (877)
267-2323.
Federal employees were granted some additional safeguards against genetic
employment discrimination in 2000, but progress has been slow in protecting
the average citizen. Legislation designed to protect the privacy of
genetic information and prohibit insurance and employment genetic discrimination
has failed several times in Congress in recent years.
Q: Decisions about diagnosis and genetic
testing can be really complicated, emotional and have far-reaching consequences.
Where can you go for help sorting it all out?
A: That's what genetic counselors are for.
"Because of the tough choices you may encounter with genetic disease,
it's good to have someone help you think through the options,"
genetic counselor Cheryl Scacheri says. "Genetics is a family thing.
Physicians don't have as much time as genetic counselors to deal with
all the surrounding issues."
A professional genetic counselor takes a detailed family medical history
and explains inheritance patterns, reproductive options and the benefits,
risks and limitations of testing. While counselors provide emotional
support, they don't advocate any particular course of action. The goal
of a professional counselor is to facilitate a family's decision making
by offering information and outlining options. Most health insurance
companies will cover genetic counseling for diagnostic purposes.
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Genetic counseling can help families
interpret the results of testing. |
"It's best not to just have genetic counseling once," Scacheri
advises. "Things change, life issues come up, nieces get pregnant,
different things come up over time. It's good to touch base every once
in a while."
No matter what you decide about undergoing testing, there's usually
a positive benefit to counseling, she notes. "People can feel better
about their decisions and not always be questioning what they're doing."
To locate a genetic counselor, ask for a referral from your MDA clinic
physician, county medical society or health department, or contact the
National Society of Genetic Counselors, at (610) 872-7608 or www.nsgc.org. |