Scenario
Tom and Sue are professors at Gallaudet University in Washington, DC. Both were born
deaf, and they married shortly after starting their careers at the university, 9 years ago.
They are interested in having children, but unwilling to bring a hearing child into their
family. Their motivation for this decision is that they perceive “deafness” not as a
disability but as a necessary attribute to fully experience their intrinsic value system.
Tom and Sue recently read the story of the Nash family and how they used
preimplantation genetic diagnosis (PGD) to select an embryo for their child. This child
was selected by PGD to be negative for Fanconi’s anemia, but positive for an immune
cell marker (HLA), allowing this child to be a suitable donor for the Nash’s first child,
who was in need of a life-saving bone marrow transplant. Knowing that their deafness
has a genetic basis, Tom and Sue approached General Hospital to request PGD on
embryos they produce from IVF, in order to select a child with the genetic sequence
linked to deafness.
Bioethics Exercise
May 25, 2005
1.)
Please read the following scenario regarding the deaf couple who has
requested to undergo PDG in an effort to choose a deaf child.
2.)
After reading the scenario, the class as a whole will identify the relevant
stakeholders in this case and write them down below. (hint: Try to identify
more than five relevant stakeholders)
STAKEHOLDERS
3.)
Once the stakeholders have been identified collectively by your class, your
instructor will assign each group the task to articulate the ethical position(s) of
the stakeholder your group was assigned.
4.)
Each group will now orally present their arguments in the form of an oral
presentation to the Executive American Reproductive Service (EARS).
5.)
Stakeholders
Arguments and final Decision
Introduction:
This is a procedure that can weed out genetically defective human embryos
before they have a chance to develop. This is usually requested by prospective
parents who are concerned about passing an incurable genetically based
disease or disorder to their child. Typically one or both partners have been
genetically screened previously, and found to be a carrier.
This "technically demanding and complex procedure" was developed only
recently. 5 Currently, it is only available in a few clinics worldwide. It involves
the following steps:
The woman is given drugs to produce "super-ovulation." She normally
produces many eggs, which are collected.
As for a standard in-vitro fertilization (IVF) procedure, the eggs are placed in
a dish and are fertilized by donated sperm (usually from the woman's
partner).
About three days after IVF, each successful embryo has divided to about the
8 cell level.
This photograph shows the start
of the procedure. Here, a 7-cell embryo which is fixed in position with a
holding pipette at the left. A second pipette, on the right is used to drill a
hole through the shell of the embryo. A single cell is dislodged from the
embryo with a gentle suction. * The procedure is typically performed on an
embryo at the 4 to 10 cells stage of development.
One or two cells are removed and "subjected to a molecular analysis. This
requires the removal of the genetic material— DNA. This minuscule amount
of DNA is amplified, meaning multiple copies are made through a molecular
process known as PCR (polymerase chain reaction). These copies are then
subjected to a molecular analysis that assists in identifying the sequence
(code) that will determine the inheritance of the gene in question." 8 If a
genetic defect is found, then the embryo from which it was taken is
destroyed.
Typically, three of the embryos which are free of abnormalities are
implanted in the woman's womb. The others are destroyed.
Sometimes, none of the embryos develop into fetuses, and the procedure is
repeated. Often one or even two embryos do live and develop into fetuses
which are later born as single births or twins.
At this time, cells can be checked for dozens of genetically determined
diseases. One site lists:
achondroplasia
adenosine deaminase deficiency
alpha-1-antitrypsin deficiency
Alzheimer disease (AAP gene)
beta thalassemia
cystic fibrosis
epidermolysis bullosa
Fanconi anemia
Gaucher disease
hemophilia A and B
Huntington disease
muscular dystrophy (Duchenne and Becker)
myotonic dystrophy
neurofibromatosis type I
OTC deficiency
p 53 cancers
phenylketonuria
retinoblastoma
retinitis pigmentosa
sickle cell disease
spinal muscular atrophy
Tay Sachs disease 11
Elsewhere on the Internet, sites also list: Fragile X syndrome, Lesch-Nyhan
syndrome - Retinitis pigmentosa, Charcot-Marie-Tooth disease, Barth's
syndrome, Turner syndrome, Down's syndrome and Rett's syndrome. Female ova
can be also be checked for a gene that increases the propensity to develop
breast cancer.
Some genetic diseases are sex-linked. For example, some are known to only be
passed on to male children. Even if a particular sex-linked disease cannot be
detected directly, the PGD method can eliminate all of the male embryos and
implant only female embryos, thus preventing the transmission of the disease.
The first "PGD baby" was born in 1989. 1,2 By 1997, over 30 babies had been
born world-wide, following the use of this technique.
Dr. Perry Phillips, an obstetrician and gynecologist, is one of the directors of
IVF Canada. He said: "This is the beginning of the end of genetic
disease…That's the dream of medicine. It's our dream. This should have the
same impact [that] antibiotics did to bacterial disease."
Current status of the procedure:
Initial PGD research was performed in the UK during the late 1980s. It remains
a rare procedure that is only available in a few clinics worldwide. It can be
used to detect about 30 conditions or diseases. There is the potential that it
will detect about 200 eventually. 10
According to the Sher Institute: "By the year 2000, more than 1500 couples had
participated in PGD clinical trials, which are ongoing in several centers around
the world, and more than 1000 PGD/IVF cycles had been performed, In
virtually all of these cases, PGD was followed by early prenatal genetic
diagnosis to eliminate the risk of misdiagnosis through PGD. Several such
errors in PGD have been recorded to date. These pregnancies were all
terminated, electively." 9
According to Anuja Dokras of the Yale University School of Medicine: "This
technique is currently available to couples whose offspring are at a high risk
(25-50%) for a specific genetic condition due to one or both parents being
carriers or affected by the disease. Also the genetic code associated with the
condition must be known in order to allow diagnosis. Currently it is not
feasible to routinely screen women at lower risks, such as women over age 35
for Downs Syndrome..." 1
An article in The Guardian, a UK newspaper quotes The Human Fertilisation
and Embryology Authority, (HFEA) as describing PGD as "a physically and
mentally demanding process which does not bring any guarantee of success."
With PGD, the live birth rate is probably even lower than the average 17% IVF
success rate, and the whole procedure is considerably more expensive. 6
Objections to the procedure:
Conservative Christians and others typically people believe that human
personhood begins at conception. This means that any destruction of an
embryo is equivalent to the murder of a human person. There are a number
of concerns that they have about PGD:
The cell that is removed could conceivably, under the right conditions,
develop into a fetus on its own. But the testing will destroy it.
The fertilized cells that are not implanted are usually destroyed, as in invitro fertilization procedures.
If a genetically defective cell is found, then the entire embryo from which
it was extracted is destroyed.
Dr. Patricia Baird, a geneticist who led the Canadian Royal Commission on
New Reproductive Technologies said: "Because there is so much money
involved, there is a real danger of premature, unwise application of this
procedure." We find this comment confusing. The procedure would cost in
the vicinity of $4,500 to $7,000 in US funds. One might argue that because of
the high expense involved, the procedure would only be applied in unusual
cases after much careful thought.
A genetically defective fertilized egg, if allowed to mature and cause a live
birth, it would not necessarily generate a disorder or disease in the
individual. Various genetic variations (called alleles) have a penetrance
factor, which is a measure of their effectiveness or power. For example, the
allele which causes Huntington's Disease has a 100% penetrance: if you have
the allele, you will certainly develop the disease. But other genetically
determined conditions have a much lower penetrance: left handedness is
only about 15%; the gene(s) that cause homosexuality have a penetrance
factor that is about 67% -- between that for Huntington's and lefthandedness. Thus, many embryos would be killed which would never have
caused a disease or disorder.
Some genetically caused diseases only develop symptoms when the person is
in their 30's or 40's. By that time, a cure might have been found.
The procedure could be the start of a slippery slope. Perhaps embryos would
be eliminated that might leave the individual at higher risk for heart disease,
or stroke, or obesity, etc. And there is the possibility that the procedure
could be used to eliminate female embryos, or embryos that would grow into
adulthood with a minority sexual orientation -- bisexuality or homosexuality.
This is an ironic situation: religious conservatives, who are most likely to
have a strong preference for a baby that would mature as a heterosexual
adult, would be exactly the group who are most opposed to PGD.
Some religious and social conservatives are worried that the technology could
lead to the creation of babies to be used for spare parts.
Advantages to the procedure
Most genetic testing now is done through amniocentesis when the fetus is 12
to 16 weeks old. The results are typically available after a wait of an
additional three weeks. In this, a sample of the amniotic fluid is drawn from
around the fetus. A floating cell from the fetus is then found and analyzed. If
the analysis shows that the fetus is genetically defective, then the parents
have the option of aborting the fetus. Essentially all couples in North America
and the UK do elect to have an abortion. Amniocentesis is be far more
distressing than Pre-Implantation Genetic Diagnosis to most couples, because
it is performed at a time in gestation when the fetus is so fully developed.
The PGD technique is performed before pregnancy begins; it would avoid
much of the stress and moral conflict in most couples. However, strongly prolife couples may not differentiate morally between the destruction of a
three-month fetus and an eight-cell embryo; they may consider both to be
fully human persons.
Some adults who know that they are carriers of a genetically transmitted
disease decide use contraception in order to not have children. The PreImplantation Genetic Diagnosis procedure allows them to have a child with
full assurance that it would not be carrying that disease. (Of course, the
child could be born with other malformations, diseases and disorders that
were not tested for.)
If the procedure became widespread, the incidence of many diseases would
be reduced.
The procedure could significantly reduce the cost of medical systems in
North America. Treatment of some genetic diseases can easily cost millions
of dollars over the lifetime of a single individual.
An alternate use for PGD:
Some people are seriously ill or dying, but can be treated or cured with a
transplant from a suitable donor. For example, people who suffer from
leukemia, aplastic anemia and other potentially life-threatening blood diseases
can often be cured with a bone marrow transplant (BMT) from a compatible
donor. Too often, sick people die because a matching donor cannot be found.
PGG offers an alternative way of finding a compatible donor -- by creating one.
The patient's mother can go through a standard IVF procedure, have many ova
harvested, have the ova fertilized by the father's sperm, and have the resulted
embryos go through a PGD procedure. If any embryos are found to contain DNA
that is an appropriate match to the patient, they can be implanted in the
mother's uterus. With luck, a pregnancy will develop and an infant will be born.
That infant may then be able to supply needed stem cells from his/her
umbilical cord or some other body component to their sibling and save their
life.
To some parents, this option is literally a life saver. Instead of watching their
child waste away and die, they can have the possibility of a cure. Also, another
child will be added to their family. The first family to go through this process
was the Nash family in Colorado. Their child "Molly was born with Fanconi
anemia, a rare genetic disease that causes many problems, the most serious of
which is inadequate bone marrow production....her poor bone marrow
production meant that she would develop leukemia and die, possibly within a
few years." The Nashes wanted a second child anyway. IVF and PGD procedures
assured that their second child would be disease free and would be a
compatible donor to their sister. A month after Adam was born Molly was
treated with radiation and chemotherapy to completely destroy her bone
marrow. She was then given a transfusion of Adam's umbilical cord blood. Her
chances of survival increased from 42% with cord blood transplant from an
unrelated marrow donor to 85% with a transplant from a matched sibling. There
was no danger at all to Adam. 13
There are some negative aspects to the use of IVF and PGD to create a child to
treat her or his sibling:
Some diseases develop too quickly to allow time for a pregnancy and perhaps
maturity of the infant to the point where they can donate.
Some people raise ethical questions about the creation of what they call
"designer babies" in order to treat a sibling.
Others object to the discarding of unused embryos. They generally feel that
human personhood starts at the instant of fertilization. They view the killing
of diseased embryos or embryos with poorly matched DNA is equivalent to
murder.
Some fear that IVF and PGD is the first step down a slippery slope that will
lead to babies being created to be used for spare parts.
Some recent developments:
1999-NOV-15: UK: Public views sought: According to the Guardian UK News:
"The human fertilisation and embryology authority, which regulates all such
work in the UK, and the advisory committee on genetic testing (ACGT)
yesterday published a consultation paper in print and on the internet. They
claim this is the first such public consultation in the world. "
"They want to know whether the public finds it acceptable for genetic
technology to be used to screen embryos to eliminate those that would be
born with distressing inherited diseases, such as cystic fibrosis. If such
screening is acceptable, the two bodies are asking, then how far should it
go? What sort of severity of disease should the labs be allowed to screen for?
If it becomes possible to detect a genetic mutation that will lead to a nonlife threatening disability such as deafness, what should be done? " 6,7
2005-APR-28: UK: Court of Appeal ruling upheld: The country's highest
appeal court ruled that couples can create embryos through in-vitro
fertilization in order to help cure sick siblings. "The Law Lords backed a
21003 Court of Appeal ruling that some couples undergoing the fertility
treatment could have their embros screened to find tissue matches for
seriously ill children, Advocates say the prodecure will help save desperately
ill children. Opponents fear it could lead to the creation of babies for spare
parts." 12
Some clinics that provide PGD:
We have found a few clinics that provide PGD and which have web sites on the
Internet. None have asked to be included on this list; none have paid to be on
the list:
California: The Reproductive Specialty Center in Newport Beach, CA. See:
http://www.drary.com/pgd.htm
Florida: The Department of Obstetrics and Gynecology, University of
Florida, at: http://www.med.ufl.edu/obgyn/pgd/
Illinois: Reproductive Genetics Institute in Chicago, IL. See:
http://www.reproductivegenetics.com/index.shtml
Oregon: Oregon Health Sciences University fertility program at:
http://www.kowhai.com/~kowhai/oregon/lab
UK: According to the The Human Fertilisation and Embryology Authority,
four centers in the UK are licensed to carry out PGD. 7
We are attempting to find a more complete list.
Books on fetal testing:
These books deal with amniocentesis. However, many of their observations may
be equally applicable to PGD.
Rayna Rapp, "Testing Women, Testing the Fetus: The Social Impact of
Amniocentesis in America," (2000). Read reviews or order this book safely
from Amazon.com online book store
Barbara Katz Rothman, "Tentative Pregnancy: How Amniocentesis Changes
the Experience of Motherhood," W.W. Norton, (1993) Read reviews or order
this book
Laurie & Keith Wexler, "The ABC's of Prenatal Diagnosis," Genassist, Inc.,
(1994). Read reviews or order this book
References:
1. Anuja Dokras, M.D.Ph.D., "Pre-Implantation Genetic Diagnosis", PreImplantation Genetic Diagnosis, Vol.1 No.5. See:
http://www.hygeia.org/
2. Fact Sheet: "Preimplantation Genetic Diagnosis", American Society for
Reproductive Medicine, 1996-DEC. See: http://www.hygeia.org/
3. J.D. Schulman et al., "Preimplantation genetic testing for Huntington
disease and certain other dominantly inherited disorders," at:
http://www.givf.com/
4. S.A. Beyler, "Diagnosis of Genetic Diseases in the Premplantation
Embryo." Lab Med, 1993; 24:642-647.
5. "Using PGD to prevent sex-linked diseases," at:
http://www.healthlibrary.com/ This web site has a remarkable series of
microphotographs, including the one shown on this page. They show how
a single cell is extracted from a seven-cell embryo. See:
http://www.healthlibrary.com/
6. Sarah Boseley, "Public views on embryo genetic testing sought,"
http://www.guardian.co.uk/
7. "Consultation document on preimplantation genetic diagnosis," The
Human Fertilisation and Embryology Authority, at:
http://www.hfea.gov.uk/
8. Luba Djurdninocic, "Pre-Implantation Testing," at: http://www.vhl.org/
9. "Pre-implantation genetic diagnosis (PGD) A commentary on its utility
and potential value," at: http://www.sirm.com/
10. "Fact sheet: Preimplantation Genetic Diagnosis, American Society for
Reproductive Medicine, at: http://www.asrm.org/ This a PDF document.
You can obtain a free software to read this type of file from Adobe.
11. Ricki Lewis, "Preimplantation Genetic Diagnosis: The next big thing?,"
The Scientist, 14[22]:16, 2000-NOV-13. See: http://www.thescientist.com/yr2000/
12. "Court lets couples create babies to cure ill siblings," The Toronto Star,
2005-APR-29, Page A16.
13. "The Nash family: miracle baby," University of Minnesota Cancer Center,
at: http://www.cancer.umn.edu/
Nature
Published online: 20 October 2004; | doi:10.1038/431894a
Genetics: Deaf by design
Carina Dennis
Carina Dennis is Nature's Australasian correspondent.
Employing genetic diagnosis to avoid having a baby with a disability is controversial
enough. But a minority of deaf people would consider testing to ensure that they had
a deaf child. Carina Dennis finds out why.
John and Karen — not their real names — are both deaf, and desperately wanted a deaf
baby. But genetic testing showed that this was extremely unlikely. "They were
devastated," recalls Arti Pandya, a clinical geneticist at Virginia Commonwealth
University in Richmond, who counselled the couple. It was two years before they got
over their disappointment and started trying to conceive their first child.
The couple's attitude will shock many people. If you can hear, it's hard to understand why
anyone would want a deaf child. But John and Karen's views are not that unusual among
those who identify themselves as 'Deaf' with a capital 'D'. The Deaf view their condition
not as a disability, but rather as the underpinning of a rich culture that should be
celebrated and preserved. And with the identification of the most common genetic
mutations linked to deafness, it is now possible, in theory, to make an active choice to
have a deaf child.
This possibility turns the debate over designer babies on its head, providing ethicists and
genetic counsellors with a dilemma. Only a tiny minority of deaf people would wish to
use genetic tests in this way. Some argue that their reproductive choices should be
respected. But is society prepared to sanction the use of genetic diagnosis for a purpose
that many find difficult to understand — and some might even see as immoral?
Some Deaf people despair of ever being understood by those who aren't part of their
culture. The Deaf identity is in large part a product of a shared sense of isolation from the
hearing world. "Exclusion is central to the experience," says Gary Kerridge, regional
disability liaison officer at the University of Ballarat in Mount Helen, Australia, who lost
his hearing as a young child.
For deaf children, the majority of whom are born to hearing parents, even family
gatherings can be lonely affairs. Many of them feel liberated by their first experience of
Deaf culture. "They learn to sign and suddenly for the first time, after years of being
isolated and struggling, they are accepted," says Kerridge. "Naturally, they quickly
develop a strong attachment to the Deaf way of life."
A world of their own
Sign language is central to the lifestyle. It uses hand shape, position and movement, plus
posture, facial expressions and other visual cues, to form words and convey meaning. It
has its own rules for grammar, punctuation and sentence order. It is elaborate and
expressive, and lends itself readily to poetry and theatre.
For a hearing person, entering a room full of chattering signers can be disconcerting.
Methods used to attract attention, for example, seem downright rude. "Stomping on
floors, waving animatedly, flashing lights and thumping tables are all considered OK,"
says Kerridge.
Knowing sign language doesn't, by itself, break down the barriers between the hearing
and the Deaf. "Even hearing people from Deaf families and who sign well are always, to
a certain degree, seen as culturally distinct," says Kerridge. "That absolute feeling of
exclusion from the hearing world is difficult for a hearing person to fathom."
Within Deaf culture, however, there's a level of social intimacy that is rare among the
hearing. "I will meet another Deaf person for the first time and in five or ten minutes, it's
not uncommon to know a great deal about their family and personal life," says Carol
Padden, a linguist at the University of California, San Diego, who was born deaf, to deaf
parents. "I have to remind myself not to expect the same invitation to become familiar
when I'm with hearing colleagues."
That, in a nutshell, is why some deaf couples would prefer to have deaf children.
Communication and the pursuit of intimacy are central to being human. If you genuinely
believe that your children will have at least as rich an emotional life if they cannot hear,
and that you will be better able to communicate with them, why not make this choice?
"I don't see anything wrong with it. I see it as being similar to how parents determine the
religion or education of their child," says Ted Supalla, who has been deaf since birth, and
studies sign languages at the University of Rochester in upstate New York. Supalla's own
children can hear; they communicate with him by sign language and speak to his hearing
wife.
Genetic lottery
Like Supalla, most deaf people are happy to let nature take its course, and say that they
would be content to have a hearing child. But deaf people are increasingly marrying one
another, making deaf children more likely. A report published in April theorized that the
increasing number of marriages among the deaf during the nineteenth century may have
doubled the frequency of deafness in the United States caused by mutations in genes for
proteins called connexin 26 and connexin 30, which affect the function of the ear's soundsensitive cochlea1.
About 1 in 1,000 infants is born profoundly deaf. About half of these cases have a genetic
cause. Mutations in many genes are involved — the most common, accounting for about
one in five deaf children, are those affecting connexin 26.
Still, most children born to deaf couples can hear. Many of the mutations involved are
recessive, which means that a baby will be deaf only if it inherits two copies of the same
mutated gene. For John and Karen, the laws of inheritance could not give them a deaf
child — their deafness is due to recessive mutations in different genes.
The couple's genetic counsellor is now investigating attitudes to genetic testing among
the deaf. In a pilot study conducted at Gallaudet University in Washington DC, a college
for the deaf and hard-of-hearing, Pandya and her colleagues asked students whether they
would be interested in considering genetic test results to help them select a partner2. More
than half of the 64 respondents said they would — but it wasn't clear from the wording of
the questionnaire whether this was because they wanted a deaf child, or a hearing one.
Pandya is planning a larger study to explore the issue further.
Using genetic tests to identify a partner with whom to try and have deaf children is one
thing; aborting a fetus if it turns out to be able to hear is another. Evidence that a small
minority of deaf people would consider this option comes from the work of Anna
Middleton, a genetic counsellor at Addenbrooke's Hospital in Cambridge, UK.
Middleton's first survey was conducted at the Deaf Nation conference, a gathering of the
culturally Deaf held in Preston in northwest England in 1997. Of the 87 delegates who
completed the questionnaire, 14 said they would be interested in prenatal testing for
deafness. Four of these said that they would prefer to have deaf children3.
Critics argued that Middleton's study was too small, and was based on a group of Deaf
activists4. So she polled a larger sample of the hard-of-hearing, hearing people with deaf
family members, and profoundly deaf people — two-thirds of whom were not culturally
Deaf. Across the deaf group, about one in five said they would consider prenatal genetic
testing, mostly to prepare for the birth of a hearing or a deaf child5.
Few of the deaf respondents said they would consider abortion, and in most of those
cases, their choice was actually for a hearing child. None of those who said they would
abort a deaf fetus was culturally Deaf. But three deaf people said they would consider
aborting a fetus if it could hear. Two of these were culturally Deaf.
Tough choices
Middleton says that it's still unclear what people would do when faced with the choice for
real. "Attitudes do not necessarily predict behaviour," she cautions. And even among
Deaf activists, it's hard to find someone who will be quoted as saying they would abort a
hearing fetus, because of the opprobrium they would attract. "Deaf people know that it's a
very risky thing to say in public that you would consider genetic testing to have a deaf
child," says Padden.
The wisdom of keeping quiet was reinforced by the controversy that engulfed Sharon
Duchesneau and Candace McCullough in April 2002. A Deaf lesbian couple from
Bethesda, Maryland, Duchesneau and McCullough told the Washington Post Magazine
that they had conceived a child using sperm donated by a deaf male friend, because they
wanted a deaf baby. They didn't employ genetic testing to guarantee success, but their
son, Gauvin, was born deaf. While the initial article was sympathetic, many of those that
followed were not. The Fox News website, for instance, ran a hostile piece, headlined
"Victims from birth: engineering defects in helpless children crosses the line".
Deaf couples wanting to be sure of having a deaf child have two options. They could use
prenatal genetic testing, and abort the fetus if it can hear. Or they could consider in vitro
fertilization (IVF) combined with preimplantation genetic diagnosis to select deaf
embryos for transfer to the womb. In December 2002, Monash IVF, a clinic in
Melbourne, Australia, conducted preimplantation tests for a couple who wanted to
exclude the one-in-four chance that they would have a deaf baby.
The Infertility Treatment Authority for the state of Victoria, which sanctioned the
Monash procedure, says it would not allow a couple hoping for a deaf child to use the
test. "Our policy states that the procedure should be used to avoid a genetic abnormality,"
says Helen Szoke, the authority's chief executive. Few other regulatory bodies have yet
devised explicit policies on the issue. Britain's Human Fertilisation and Embryology
Authority, for instance, which issues licences for preimplantation genetic testing on a
case-by-case basis, has not yet had to rule on the matter. The UK Human Genetics
Commission, meanwhile, is currently preparing a report for the government on genetics
and reproductive decision-making, which may touch upon the issue.
Prenatal genetic testing for hereditary conditions is used more widely than
preimplantation diagnosis. And in many countries, including the United States, there are
no legal restrictions on its use. Instead, clinical geneticists and genetic counsellors would
have to decide whether to assist a deaf couple to have a deaf child by giving them a test
that could lead the parents to abort a hearing fetus.
An international survey of 2,906 geneticists in 36 nations revealed varying views on this
point. In Norway, none of those surveyed would perform such a test, and in France, the
figure was just 1%. But in the United States, Italy, Russia, Cuba and Israel, more than a
third said they would6.
In practice, such tests are far more likely to be used by hearing couples to avoid having a
deaf baby. In July, The New York Times highlighted the case of a couple who had taken a
series of genetic tests before conceiving to be sure that they weren't at risk of passing on a
genetic disease. When their deaf son was born, the parents were angry that they hadn't
been tested for the common mutations that can cause deafness.
For many people born deaf, including Padden, the attitudes revealed in the piece struck
close to home. "That article sent chills down my spine," she says. Middleton's surveys
suggest that many deaf people feel similarly. The culturally Deaf, in particular, feel
threatened by the possibility of genetic diagnosis leading to the abortion of deaf fetuses3.
Some postings on deaf online forums have equated genetic testing with Nazi-style
eugenics. Similar attitudes underpin widespread Deaf opposition to the idea of 'curing'
deaf people using cochlear implants.
Testing times
This unease may explain why Middleton's surveys have shown that deaf people are less
likely than the hearing to consider prenatal testing for deafness3, 5. And among those who
would consider testing, opinions vary widely. Many deaf people, for instance, are
appalled by the idea of aborting a fetus if it can hear. Opinions may depend in part on
whether the individual was born deaf or lost their hearing later on, and whether they grew
up in a deaf family.
Given these diverse viewpoints, some experts argue that it's unfair to focus on the
minority of the culturally Deaf who say they would consider aborting a hearing fetus. "It
is offensive to keep harping on about this scenario. While many deaf parents may harbour
a preference for having deaf children, the data suggest that the majority would never
consider doing it," says Barbara Biesecker, a genetic counsellor at the National Human
Genome Research Institute in Bethesda.
But if genetic testing to screen against deafness takes off, and the Deaf feel that their
culture is threatened, it's possible that some will want to fight back. In this case, their best
option might be to adopt the very technology they fear, and embrace genetic testing to
ensure that they have deaf children.
It's even possible that some may have already done so, without anyone realizing. In many
countries, there are no legal obstacles to stop a woman obtaining a prenatal test for
deafness, without revealing her true motivations, and then seeking an abortion from a
different healthcare provider if the result showed that she was carrying a hearing fetus. "If
the question is whether there are any restraints to prevent somebody from doing this, the
answer is no," says Biesecker.
Top
References
1. Nance, W. E. & Kearsey, M. J. Am. J. Hum. Genet. 74, 1081-1087
(2004). | Article | PubMed | ISI | ChemPort |
2. Taneya, P. R., Pandya, A., Foley, D. L., Nicely, L. V. & Arnos, K. S. Am. J. Med.
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