Genetic Testing and Genetic Engineering - University of Toronto

neighgreasycornerBiotechnologie

14 déc. 2012 (il y a 8 années et 7 mois)

270 vue(s)

Defining Disease &

Genetic Testing


PHL281Y Bioethics

Summer 2005 University of Toronto

Prof. Kirstin Borgerson

Course Website: www.chass.utoronto.ca/~kirstin


Announcement



http://www.artsandscience.utoronto.ca/
current/exams/august.html



Monday, Aug.15
th

7
-
10pm GB 304



GB = Galbraith Building (35 St. George)

Overview


1.
Defining Disease


2.
Geneticization and prenatal genetic testing (Lippman)


3.
3 arguments against prenatal genetic testing and selective
(genetic) abortion (Kass)


4.
1 argument for genetic testing and preventing conception
(Purdy)



Defining Disease


Why?



Disability and disease



Disease states give rise to special claims on society



Disease may be misused


blaming the individual for social
problems or blaming society for individual problems



We want to cure disease, but we may end up trying to ‘cure’
diversity and difference


Disease



Drapetomania’ (19
th

century)


the disease causing slaves
to run away



‘Dysaesthesia Aethiopis’ (19
th

century)


hebetude of mind
and obtuse sensibility of body


a disease peculiar to
negroes [sic]


called by overseers ‘rascality’



‘Hysteria’ in women throughout history



As recently as 1980
-

DSM
-
III, as a personality
--
invariably
female
--
described as histrionic, prone to exaggeration,
shallow, demanding, seductive, egocentric, romantic, and
manipulative



Numerous writers have traced this to a caricature male
medical view of femininity


Disease


Example 1: masturbation



Moral undertones to classification (‘you are deviant/bad’ to ‘you are
ill/defective’)


Sexual overindulgence was generally considered debilitating
-

Hippocrates


Masturbation in particular was widely accepted as a disease from
about 1700


Held to be the cause of: dyspepsia, constrictions of the urethra,
epilepsy, blindness, vertigo, loss of hearing, headache, impotency,
loss of memory, irregular action of the heart, rickets, leucorrhea in
women, chronic catarrhal conjunctivitis, nymphomania in women,
changes in external genitalia… and studies ‘demonstrated’ links to
insanity, consumption, and general debility


and even death


Treated with: restraining devices, infibulation, circumcision, acid
burns, thermoelectrocautery, clitoridectomy, vasectomy,
institutionalization (insane asylums), castration, dietary changes,
sexual intercourse…


Disease


Example 2: homosexuality



Originally classified as a psychological disorder
(declassified from the
DSM

in 1973)



When homosexuality was identified as a disease:


Criminalization


Forced ‘cures: hypnosis, aversion therapy (nausea
producing drugs), electric shock, castration…



Defining Disease


Definition of disease:



Naturalist


value
-
free, deviation from species
-
typical
functioning


Ex// mammal


Normativist



value
-
laden, matter of subjective
evaluation and experience (socially and culturally
influenced)


Ex// weed



Illness/disease

Defining Disease


Merck Manual of Diagnosis and
Therapy / Diagnostic and Statistical
Manual of Mental Disorders (DSM) IV



Medicalize = “To give a medical
character to; to involve medicine or
medical workers in; to view or
interpret in (esp. unnecessarily)
medical terms” (
OED
)



"Since disease is such a fluid and
political concept, the providers can
essentially create their own demand
by
broadening the definitions of
diseases

in such a way as to include
the greatest number of people, and by
spinning out new diseases" Lynn
Payer
Disease Mongering


Disease Mongering?

1.
Ordinary processes or ailments as medical problems


Baldness, pregnancy, menopause, aging, infertility


2.
Mild symptoms as serious disease


Irritable bowel syndrome, chronic fatigue syndrome


3.
Personal or social problems as medical ones


Social phobia , criminal behavior, drug dependence, eating
disorders, alcoholism


4.
Risks conceptualized as disease


Osteoporosis (reduced bone mass), high blood pressure, high
cholesterol


5.
Disease prevalence estimates framed to maximize the size of a
medical problem


Erectile dysfunction, female sexual dysfunction, hyperactivity in
children/ ADD/ ADHD, PMS/ PMDD (Pre
-
Menstrual Dysphoric
Disorder), depression

Implications and Discussion


Profit and disease



Can we get rid of the social element in our definition
of disease?

Genetic Testing
-

Context



Prenatal diagnostic techniques



In the last 20
-
30 years, vast increase


Ultrasound is now customary in North America (despite
evidence indicating it is not necessary for normal low
-
risk
pregnancies)


Amniocentesis


Chorionic Villus Sampling (CVS)


Often implicit assumption of abortion will follow from diagnosis
of a fetal abnormality



Prenatal treatment (promised)


Justice and Genetic Testing


Lippman



North American Culture


The illusion of choice
and control

Disease



Lippman (16) talks about the social construction of disease
categories




This is extended to an analysis of the social construction of
medical ‘needs’


Ex/ prenatal testing




In recent years it seems as though both diseases and medical
needs are being shaped by talk of genetics (metaphor of
‘blueprints’)

Geneticization


Geneticization

= “the ongoing process by which
differences between individuals are reduced to their
DNA codes, with most disorders, behaviors and
physiological variations defined, at least in part, as
genetic in origin” (19)



Ties to medicalization


Emphasizes genetic determinism


Promotes scientific/technological control of the body


Individualizes health problems


Identifies and categorizes individuals according to their
genes


Genetics is ‘the’ way to explain health and disease

Why is this a concern?


Resources diverted from more serious diseases and ‘real’
needs (opportunity costs and economic waste)



Obscures social & economic determinants of health



Ex/ low birth weight more likely caused by factors other than genetics
(poverty, for instance)



Low tech. health solutions are ignored though they are
often cheaper, simpler, and more effective



Nutritional, hygienic, social, economic, political and other supportive
services

Why prenatal testing?

1.
Reassurance for Women


2.
Reasons of Reproductive Autonomy


Expanded reproductive choices and control for
women


3.
Public Health Reasons


Decreases frequency of birth defects in the
population





Underlying assumptions?


1. Reassurance: Constructing
‘Needs’


Features of childbearing in North America that shape ‘needs’:



Major responsibility for family health, especially of children, allocated to
women (27)


Pregnant woman is expected to produce a healthy child, and to do
everything for the fetus


If a woman doesn’t choose prenatal testing, it can easily be seen as
negligent


because the technology exists, burden of not doing enough



Pregnant woman are bombarded with behavioral directives, which foster a
sense of incompetence and a need for external verification


Women as ‘uterine environment’ that must be tested to ensure
adequate adherence to rules about smoking, drinking, eating,
exercising, taking medication, etc.



Pregnant women classified as ‘high risk’ (those over 35, for example) feel
extra social pressure to test



As more ‘at risk’ women get tested, risks seem more ominous (though the
frequency of, for example, Down’s syndrome, has not changed)






Reassurance



It would probably reassure many pregnant women if they
had guaranteed access to:



Nutritional, social and other supportive services


Funding for home visitors, respite care and domestic
alterations


And if they knew treatments and medications were
under development for disorders and diseases affecting
infants



Suggestion: ‘map’ and ‘locate’ most significant causes of
disease (ex/ low birth weight & prematurity)

2. Reproductive autonomy?



Prenatal testing is sold as offering women more control and
choice


But who actually gains more control over pregnancy?
(Obstetricians, geneticists, insurance companies,
governments, society)



Prenatal diagnosis cannot be an autonomous choice when no
alternatives are available



Ex/ What if prenatal screening becomes available for PKU but
there is no insurance to cover diets for kids with PKU (in USA).
How real is this choice?




The social context is such that no alternatives are available
(especially to those less educated, and especially in light of the
lax informed consent requirements in this area)

3. Public Health?



Reduce the frequency of birth defects


Inflated ‘need’


Value judgments and eugenics?

Justice


Often focus on distributive justice so it all becomes about
increasing choice and control


Ex/ make sure everyone has equal access to genetic testing



At cost to social justice, corrective justice


Ex/ Are people generally doing better as a result of genetic
testing? Does genetic testing exacerbate or improve on the
inequalities traditionally arising in health care?



Need greater balance



Wolf

Kass


3 arguments against prenatal genetic testing and
selective (genetic) abortion:


1.
Equality of the Fetus


2.
Equality of the ‘Genetically Abnormal’


3.
Slippery Slope

1. Equality of the Fetus Argument


1.
Human beings are (radically) morally equal: all
possess certain fundamental rights, including the
right to life


1.
Aborting a fetus because of a genetic defect
denies the fetus’ radical moral equality


1.
Therefore, genetic abortion is morally
impermissible


Objection




Equivocation


Human Being = genetic /
biological human


Human Being = moral
person


Reply


Deeper problem of equality persists. The
reason

given
for aborting the fetus is now ‘because of genetic defect’
which implies that the decision about whether to abort
lies on different grounds than in standard cases of
abortion



In other words, even people who believe the value of a
fetus is very low (close to zero) are meant to be
committed to a principle valuing all fetuses equally at
this (low) level. Aborting one fetus and not another for
reasons of genetic disease implies a difference in value



Unless…


May be justifiable if the decision is made ‘because of a
quality of future life assessment’


‘Potential persons’?


2. Equality of the ‘Genetically
Abnormal’ Argument



1.
If genetic abortion is common practice, then we will think
that those living with genetic defects ought not to have been
born


2.
If we think that those living with genetic defects ought not
to have been born, then we will not treat them with full
moral respect


3.
To adhere to our belief in the radical moral equality of all
human beings, we must treat all human beings with full
moral respect


4.
Therefore, to adhere to our belief in radical moral equality,
we ought not to accept genetic abortion


Objection


Objection: speculative empirical claims


‘we will think those living with genetic defects
ought not to have been born’


‘we will not treat them with full moral respect’



Reply?


3. Slippery Slope Argument


1.
Genetic testing and genetic abortion are morally
permissible


2.
Genetically defective humans should not be born [from 1]


3.
The genetic character of a defect is an accidental or
morally irrelevant feature of the defect


4.
Therefore, defective humans should not be born [from
2,3]


5.
Therefore, defective humans should be eliminated [from
4]




Eugenics



Application of the principles of genetics to the
production of ‘improved’ offspring


Eugenics


1915 New York

So…


Can we draw a line between prenatal genetic
testing and genetic abortion?



Or between genetic abortion and a principle
of ‘eliminating defective newborns’?



Or between the principle of ‘eliminating
defective newborns’ and eugenics?



Or…


Purdy: Genetic Testing

and Reproduction




Huntington's Disease (HD)
: “a devastating, hereditary,
degenerative brain disorder for which there is, at present, no effective
treatment or cure. HD slowly diminishes the affected individual's
ability to walk, think, talk and reason. Eventually, the person with HD
becomes totally dependent upon others for his or her care.
Huntington's Disease profoundly affects the lives of entire families
--

emotionally, socially and economically…



Early symptoms: depression, mood swings, forgetfulness, clumsiness,
involuntary twitching and lack of coordination



Later symptoms: concentration and short
-
term memory diminish and
involuntary movements of the head, trunk and limbs increase.
Walking, speaking and swallowing abilities deteriorate. Eventually the
person is unable to care for him or herself. Death follows from
complications such as choking, infection or heart failure”

Huntington’s Disease


“HD typically begins in mid
-
life, between the ages of 30 and
45, though onset may occur as early as the age of 2.
Children who develop the juvenile form of the disease
rarely live to adulthood…



HD affects males and females equally and crosses all ethnic
and racial boundaries. Each child of a person with HD has a
50/50 chance of inheriting the fatal gene. Everyone who
carries the gene will develop the disease. In 1993, the HD
gene was isolated and a direct genetic test developed which
can accurately determine whether a person carries the HD
gene. The test cannot predict when symptoms will begin.
However, in the absence of a cure, some individuals "at
risk" elect not to take the test”

(Huntington’s Disease Society of America (
www.hdsa.org
))





Reproductive Threshold


Moral Minimalism


“it is morally permissible to
conceive individuals so long as we do not expect them
to be so miserable that they wish they were dead”


Puts no demands on us


Not many people would want to live in a world where this was
the prevailing standard


Doesn’t pay much attention to human well
-
being



Minimally Satisfying Lives


“we ought to try to
provide every child with something like a minimally
satisfying life” (523)


Minimally satisfying = many elements. Purdy focuses on
‘health normal for that culture’ (for this argument)


Huntington’s disease does not meet this standard (in virtually
all societies) according to Purdy

Purdy’s Argument

1.
We ought to provide every person with a minimally satisfying
life [from Utilitarian or Contractarian moral theory]


2.
People with HD* are unlikely to live a minimally satisfying life
[empirical claim]


3.
People currently living with HD are at high risk of passing on HD
to their children


4.
We ought to prohibit people currently living with HD from
having genetically related children


5.
People currently living with HD are morally obligated to prevent
the conception of genetically related children (or test for and
abort fetuses with HD)



*Huntington’s disease is used here but may be replace by any
other genetic disease that we know to be the cause of a life that
is not minimally satisfying as defined by Purdy


Analysis


Objection: Right to reproduce



What reasons do we have for this right?



Love, companionship, shaping a new generation?


Reply: adoption, AI, egg donation, IVF, cloning



Immortality, mini
-
me?


Reply: narcissistic? false?



Objection: Right not to know


Defensible only when ignorance does not put others at
serious risk



Implications?

Genetic Engineering


Treatment


Enhancement

Contact

Prof. Kirstin Borgerson

Room
359S

Munk Centre

Office Hours: Tuesday 3
-
5pm and by appointment

Course Website:
www.chass.utoronto.ca/~kirstin

Email: kirstin@chass.utoronto.ca