Transcript Chapter 3 Genetic Control

Chapter 3 Genetic Control
Challenge of genetic control
• It’s long been known that who we are depends in part on our
environment and in part on our parents. This old and familiar idea
was given greater clarity and precision with the discovery of DNA as
the chemical basis of heredity.
• This increased understanding also took a practical turn: within
limits, we are better able to testi for the genetic factors underlying
diseases and even non-disease traits.
• Newfound knowledge and ability can result in new ethical
questions.
• The increased understanding of genetics, and in particular, of the
ability to test for particular genes, has resulted in a set of ethical
questions, some of which are discussed in this chapter.
Section 1: Dilemmas of Genetic Choice
• Genetic screening, counseling prenatal diagnosis, and
embryo selection offer the prospect of avoiding the
misery caused by crippling or fatal genetic diseases.
• If a genetic disorder can be detected before birth, it is
possible to prevent the birth of children with those
diseases. This would be of benefit to all including the
children who might have been born.
• Yet, as positive as this outcome might appear, the
possibility of genetic choice raises a number of
troubling ethical issues, among them are:
Dilemmas of genetic choice
• Diagnostic procedures themselves present a possible
risk to the mother or fetus. When are those risks
justified?
• In most cases in which prenatal diagnosis indicates that
the fetus suffers from a genetic disorder or
developmental defect, the only means of avoiding the
birth of an impaired child is abortion.
• But is abortion morally justified? If it is not, then is prenatal genetic screening justified? (Chapter 5 examines
the morality of abortion in detail.)
Dilemmas of genetic choice
• A similar moral question arises in connection with embryo selection which
is possible through In Vitro Fertilization.
• With this procedure, several of a woman’s eggs are fertilized outside her
body and allowed to develop into early-stage embryos. During this time it
is possible to screen the embryos for defects and to select only those
which are free of them for implantation in the uterus.
• What are our moral obligations, if any, to the defective embryos not
chosen?
• Prospective parents who learn through genetic testing that giving birth
will possibly or likely result in an impaired child might decide nonetheless
to go forward with the birth. Do they have right to do so?
Dilemmas of genetic choice
• Children born with genetic diseases and defects require the
expenditure of large amounts of public funds. Given these
costs, is society justified in requiring that people submit to
genetic screening, counseling, or prenatal diagnosis?
• Do physicians have an obligation to inform their patients
who are prospective parents about the kinds of genetic
tests that are available?
• What if a doctor is opposed to abortion and is afraid that
his patient would seek one if the results of screening
revealed a genetic defect?
Reading: The Morality of Screening for Disability
Jeff McMahan
McMahan reviews four common objections to prenatal
or pre-implantation screening for disabilities:
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screening is discriminatory
has harmful consequences for disabled people
expresses a hurtful view of disabled people
reduces human diversity.
Reading: The Morality of Screening for Disability
Jeff McMahan
• If these objections show that screening is wrong, McMahan
argues, they also imply that it is permissible to cause
oneself to have a disabled child.
• Those who accept the objections to screening and claim
that being disabled is no worse than being nondisabled
seem committed to accepting that it is permissible to
deliberately cause a disability prenatally, even for a trivial
reason.
• If we find this view unacceptable, McMahan claims, then
we must find the objections to prenatal screening for
disability wrong.
Reading: Genetic Dilemmas and the Child’s Right to an
Open Future
Dena S. Davis
• Davis asks whether genetic counselors must assist
couples who wish to have a child who will be deaf
or an achondroplasia dwarf.
• Taking deafness as an example, she argues that
although counselors are professionally
committed to an ethic of patient autonomy they
may reject such a request, on the ground that it
would limit the future autonomy of any child that
might be born.
Reading: Genetic Dilemmas and the Child’s Right to an
Open Future
Dena S. Davis
• Davis compares the situation with one in which Jehovah’s
Witnesses refuse to consent to a lifesaving blood transfusion for
their child and one in which Amish parents remove their children
from school after the eighth grade.
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While courts have allowed the second, Davis sees both as
unjustifiably denying children an “open future.”
• Whether or not deafness is considered a disability in a culture,
being born deaf significantly restricts the choices open to a child.
Thus, if it is chosen before birth by the child’s parents, it must be
considered a harm. For this reason, genetic counselors should not
help parents produce deaf children.
Section 2 Genetic Selection: A New Eugenics?
• The goal of genetic screening is typically understood to
be to detect genetic defects before birth.
• But, as our understanding of genetics increases, it may
soon be possible to identify genes responsible for
positive traits, such as intelligence or good memory.
• Assuming that this possibility becomes a reality, what
should our moral stance be towards selecting for such
traits (producing “designer babies”)?
Reading: Procreative Beneficence: Why We Should
Select the Best Children
Julian Savulescu
• Julian Savulescu argues that if tests for non-disease
genes become available, we have a moral obligation to
use them in making decisions about reproduction.
• Because disease-causing genes reduce the well-being
of a person, what he calls the “principle of Procreative
Benevolence” directs us to select against them. It isn’t
the disease itself we are selecting against, Savulescu
claims, but its impact on a life. But non-disease genes
can also have an impact. Intelligence, for example, can
also affect well-being.
Reading: Procreative Beneficence: Why We Should
Select the Best Children
Julian Savulescu
• Thus, genetic information about qualities relevant
to it should be used to select the embryo or
fetus, with the aim of producing a life of the
greatest well-being. Procreative Beneficence,
Savulescu holds, must be balanced against
Procreative Autonomy.
• Even so, doctors should try to persuade potential
parents to seek out and use genetic information
that will let them select for the greatest possible
well-being in the life to be created.
Section 3: Genetics and Abortion
• The goal of genetic testing is to provide
information to doctors, patients and prospective
parents so that they can make informed
decisions.
• One kind of decision concerns possible medical
treatments. For example, if a woman knows that
she carries a gene (such as BRCA-1) which
increases her chances of familial breast cancer,
she might elect to have a radical mastectomy.
Section 3: Genetics and Abortion
• Another kind of decision concerns whether to
carry a pregnancy to term or have an abortion.
• The morality of abortion is a familiar question
explored in depth in Chapter 5.
• In this section, the authors examine a narrower
issue: abortion aside, are there any moral limits
to the use of pre-natal testing?
Reading: Fetal Privacy and Confidentiality
Jeffrey R. Botkin
• Botkin argues for placing legal and ethical limits on
prenatal testing.
• A woman’s right to get information about her fetus, he
claims, is not derived from the right to privacy, which
justifies her decision to have an abortion. Rather, it is
derived from the doctrine of informed consent.
• When she seeks prenatal care, she is entitled to receive
information not only about herself, but about the
health of her fetus.
Reading: Fetal Privacy and Confidentiality
Jeffrey R. Botkin
• As with other sorts of communication between a
doctor and a patient, the information the doctor
should disclose is subject to rational limits.
• These limits include protecting the fetus’s right to
privacy, a right that must be balanced against the
potential harm the birth of the fetus poses for the
parents.
• Prenatal testing is justified, Botkin concludes, when the
harm the fetus poses is similar in magnitude to the
birth of an unwanted child.
Reading: Implications of Prenatal Diagnosis for the
Human Right to Life
Leon R. Kass
• Leon Kass expresses concern that the practice of
“genetic abortion” will strongly affect our attitudes
toward all who are “defective” or abnormal.
• Those who escape the net of selective abortion
might receive less care and might even come to think
of themselves as second-class specimens.
Reading: Implications of Prenatal Diagnosis for the
Human Right to Life
Leon R. Kass
• Kass presents six criteria that he suggests ought to be satisfied to
justify the abortion of a fetus for genetic reasons.
• He focuses on the question raised by the last criterion: according to
what standards should we judge a fetus with genetic abnormalities
unfit to live?
• As candidates for such standards, Kass examines the concepts of
social good, family good, and the “healthy and sound” fetus.
• He finds difficulty with all, and in the end he professes himself
unable to provide a satisfactory justification for genetic abortion.
Section 4: Embryonic Stem Cells: End of the
Battle?
• Embryonic stem cells are undifferentiated cells
produced after a fertilized egg has divided several
times and developed into a blastocyst.
• The blastocyst, a hollow ball of cells, contains a little
lump called the inner-cell mass consisting of fifteen to
twenty embryonic stem cells.
• As development proceeds, embryonic stem cells
differentiate and become specialized. They turn into
so-called adult stem cells. These cells go on to produce
the approximately 120 different cell types.
Section 4: Embryonic Stem Cells: End of the
Battle?
• Before embryonic stem cells begin to differentiate,
they have the potential to become any of the
specialized cells. It is because of this potentiality that
researchers have thought they might be used to treat
many chronic, debilitating, and life-threatening
diseases.
• However, because retrieving embryonic stem cells
often results in the destruction of the embryo itself,
some of the moral objections raised against abortion
are also raised against embryonic stem cell research.
Section 4: Embryonic Stem Cells: End of the
Battle?
• But new research raises the possibility of being able to
take a somatic cell, such as a skin cell, and “reprogram”
it back to its earlier, undifferentiated adult stem cell
status. As an adult stem cell, the cell could potentially
be made to differentiate into any other cell type, as
embryonic stem cells are able to do.
• The immediate appeal of being able to acquire human
embryonic stem cells by converting somatic cells is the
possibility that researchers will no longer need to
create or destroy human embryos.
Section 4: Embryonic Stem Cells: End of the
Battle?
• Thus, the arguments over the moral legitimacy
of stem-cell research and treatments based on
stem cells should significantly abate, if not
wholly disappear.
• But, as the readings in this section make clear,
this promise is not as obvious as it might at
first appear.
Reading: Stem Cells from Skin Cells: The Ethical
Questions
Insoo Hyun
• Hyun argues that the genetic modifications of
human skin cells to be like embryonic stem cells,
though exciting, will not remove the ethical
problems of stem cell research.
• First, induced pluripotent stem cell (iPS cell)
research will have to be carried out in
conjunction with embryonic stem cell research in
order to determine their value and safety for
clinical applications.
Reading: Stem Cells from Skin Cells: The Ethical
Questions
Insoo Hyun
• Second, the use of iPS cells will raise complicated issues of
informed consent because they will be solicited from
gravely ill patients whose hopes might easily be exploited,
as might, those of future patients who may seek
treatments with iPS cells.
• Finally, iPS cell research may come up against the same
questions about personhood as embryonic stem cells if it
turns out that somatic cells can be programmed to
generate supporting extra-embryonic (placental) tissues
needed for the embryo to develop into a fetus or if iPS cells
can be programmed to generate human sex cells.
Reading: Ontological and Ethical Implications of Direct
Nuclear Reprogramming
Gerard Magill and William B. Neaves
• Magill and Neaves argue that the 2007 scientific
breakthrough of producing induced pluripotent stem
cells (iPS cells) from human skin cells has ethical
implications for how we regard natural human
embryos, as well as embryos produced by cloning (i.e.,
somatic cell nuclear transfer.)
• The iPS cells share with embryos the potential to
develop, given the right conditions, into a late-term
fetus. Further research may show that iPS cells, like
embryos, can also make their own placentas.
Reading: Ontological and Ethical Implications of Direct
Nuclear Reprogramming
Gerard Magill and William B. Neaves
• This would make them indistinguishable in relevant ways
from embryos (however produced).
• Thus, those who consider an embryo the moral equivalent
of a person and seek to protect them must either extend
the same protection to iPS cells or change the criteria for
personhood to ones that rely on features from a later state
of embryonic development.
• Otherwise, defenders of the embryo-as-person view must
reject using iPS cells for therapeutic purposes, in the same
way that they reject the destruction of embryos and
cloning.
Reading: Declaration on the Production and the Scientific and
Therapeutic Use of Human Embryonic Stem Cells
Pontifical Academy for Life
• The declaration by the Pontifical Academy sets
out the official Roman Catholic position on the
moral aspects of acquiring and using human
embryonic stem cells.
• The Academy declares it is not morally legitimate
to produce or use human embryos as a source of
stem cells, nor is it acceptable to use stem cells
from cell lines already established.
Reading: Declaration on the Production and the Scientific and
Therapeutic Use of Human Embryonic Stem Cells
Pontifical Academy for Life
• The Academy endorses the idea of directing
research toward using adult stem cells to achieve
the benefits that it is hoped embryonic stem cells
might achieve.
• In 2008, the congregation for the Doctrine of the
Faith issued “Instruction Dignitas Personae on
Certain Bioethical Questions,” in which it
reaffirmed these positions and justification.