Download Preimplantation diagnosis is disease control, not eugenics

Human Reproduction vol.11 no.3 pp.463-464, 1996
OPINION
Preimplantation diagnosis is disease control, not
eugenics
Joseph D.Schulman1-3 and ILG.Edwards2
'Genetics & IVF Institute, 3020 Javier Road, Fairfax, VA 22031,
USA and ^urchill College, Cambridge, UK
'To whom correspondence should be addressed
The possibility of diagnosing genetic disease in human
embryos, using X- or Y- linked genes, or genes specific to the
autosomes has been on the cards for 25 years (Gardner and
Edwards, 1968; Fowler and Edwards, 1973). So too have the
wider genetic implications of gene diagnosis in embryos,
including the scientific and social implications of selecting for
various 'desired' genes. The 'Opinion' of Testart and Sele
(1995) now links again the use of methods introduced for
preimplantation diagnosis to a debate on the eugenic implications of a selection for socially-desired characteristics in human
embryos.
We question many statements in their manuscript and the
overall expression of their views. Their main thrust is to
present preimplantation diagnosis as a vehicle of eugenics
more powerful than any of its predecessors, perhaps more
acceptable than other forms of prenatal diagnosis to some
patients, and therefore more widely to be feared. They attempt
to seize high moral ground by applying the term 'eugenics' to
what others would simply identify as parental choices used to
reduce the risks of certain birth defects in their offspring. This
highly evocative word has been dragged into disrepute by its
various historical associations. Its very definition makes clear
its focus on populations, not on individuals. Webster's New
Collegiate Dictionary defines eugenics as a 'discipline that
deals with the improvement (as by control of human mating)
of hereditary qualities of race or breed'. The freely-chosen
desire of an individual couple to reduce the frequency of cystic
fibrosis, for example, in their offspring is considered by most
members of society to rightly be a matter of individual choice
for them, and not a matter of eugenics. The couple's choice
is not a part of a grand design to 'improve' the human race
according to a predetermined plan which, in the words of
Testart and Sele, 'would conform better to the social and
economic ideal'. Nor is preimplantation diagnosis likely in its
present form to make such an impact.
Some of their statements cannot be disputed, such as
'genes interact with environmental factors limiting genetic
determinism'. This is obvious. They employ the strategy of
using labels which obscure the issues under discussion and
give the proponents of certain points of view a superficial
claim to high moral position. They create straw men, artificially
© European Society for Human Reproduction and Embryology
set up only to be knocked down. Examples abound. The issue
is defined as 'efficient medical eugenics' and the authors ask
in their title 'Is the desirable always the feasible?' The only
possible answer is 'of course not'. Similarly the feasible is
transparently not always the desirable. The manuscript is
replete with rhetorical questions, with deeply questionable
underlying premises such as 'If the choice that parents impose
on children is not truly theirs, then whose is it?' and utterly
unproven, and perhaps unprovable, assertions such as 'Embryonic screening is a tool for the social exclusion of deviants
and for the exacerbation of competition between human
beings'. The ethical posturing is evident for who indeed wants
to rise up to defend the further enhancement of competition
in an already highly competitive, high pressure world?
And, at last, the authors use their 'chain of reasoning' to
conclude that "The fear of these perspectives led to an
examination of the various means of restraining the use of
preimplantation diagnosis', which is obviously their mission.
They correctly realize that central committees and genetic
elites cannot do this job for a variety of reasons, including
that 'medical tourism would limit access to eugenics only to
those who could afford it'. They assert that 'genetic problems
are more complex than we are led to believe', providing no
evidence that anyone feels that human genetics is not complex,
and they close with the conclusion that such problems should
be approached with a 'determined humility to uphold the
ethical dimensions of life', as if anyone had ever advised that
it should not
We agree with Testart and Sele that the new technologies
cannot and should not rest with 'controlling committees' or a
'short list of doctors and geneticists', and should not be applied
to a 'list (to) be legally established' of certain genetic illnesses.
We have already witnessed the problems in assisted reproduction created by 'experts' in certain countries including France,
who tried to decide what is right and good for every one
in such areas as genetic testing, human embryology and
reproduction. Indeed, an analysis of the variations between
countries in their outlook on assisted reproduction and genetics
could legitimately be the subject of another editorial. But
where Testart and Sele see no good solution to the 'problems'
of medically assisted procreation, and retreat into opposition
and moral posturing, we see an enhancement of the freedom
of parents and potential parents to reduce the enormous burden
of genetic illness in their individual families. We trust in the
great majority of people to wisely decide on the use of new
genetic and reproductive technologies in their own personal
463
J.D-Schulman and R.G.Edwards
situations, and in the good sense of those who have the
technical and professional skills to provide, or not to provide,
the complex services involved. Our confidence is also grounded
in reality, since in contrast to various doomsday assertions we
submit that experience of the medical applications of genetic
and reproductive technologies to informed individuals has
been and will be enormously positive for mankind.
There are clear limits to what preimplantation diagnosis can
actually do. Single gene defects in embryos can already be
identified with confidence. Several genes can already now be
identified in a single cell (Findlay et al, 1995), and some
quasi-quantitative characteristics might soon be diagnosed in
human preimplantation embryos. Many of the major human
traits are highly polygenic, and a large number of genes may
possibly be analysed in embryos in the near future. But
more embryos may be needed to obtain the desired genetic
combinations than a woman can produce in a lifetime. And
the chosen combination might still produce a child of low
intelligence or aptitude for whatever 'important' characteristics
were or were not being selected for. We have been through
all of this with cloning, and the same answer always emerges:
that such a chase is unworthy of the human race, and is
dwarfed by the far worthier aim of providing universal, high
quality education and training for as many children as possible.
If we do have one concern, it is that our subject, genetics,
is now being used in preimplantation and prenatal diagnosis
for expensive and suboptimal approaches to human genetic
disease. Genetics has provided fundamental understanding to
biology, the modem principles of molecular biology, embryology, the evolution of species and individual variability. Yet
today, we witness with sadness some of the consequences
when an inherited human disease is characterized. A gene
sequence for an inherited disease is identified to fanfares from
the press, yet within a few months or years the sequence may
be used to detect and destroy a human fetus with this inherited
disease. Brilliant genetics thus leads to a series of subsequent
abortions. We are deeply conscious of the despair of a couple
faced with a severely disabled child, and accept the decision
to terminate an afflicted pregnancy. But different approaches
to the challenges of clinical genetic diseases are also needed.
Stem cells, perhaps genetically tailored beforehand, might be
transplanted into embryos identified with genetic disease from
outgrowths of blastocysts or from donors free of a particular
disease. This approach can now be contemplated at the
astonishingly early fetal (embryonic) age of 28 days postfertilization (Jurkovic etal, 1994, 1995; Edwards etai, 1995).
We anticipate the introduction of germinal DNA therapy, or
somatic therapy to alleviate the symptoms of inherited disease
(Coutelle et al, 1995). None of us knows what hidden talents
may be associated with fetuses that are being aborted because
they carry a single gene defect
In any case, prenatal clinical genetics has already raised
complex issues which also invdlve preimplantation diagnosis.
A positive diagnosis of, for example, the dominant gene for
Huntington's chorea in a fetus implies that one of the parents
is affected, and must face the personal consequences of this
diagnosis. There are several other late-onset genes such as
this, perhaps even genes predisposing to cancer (Struewing
464
et al, 1995), where diagnosis could result in the carrier being
'typed' socially for the affliction by employers, insurance
societies and even by potential marriage partners. This scenario
makes us most desirous of introducing alternative strategies
(Schulman et al, in press) including eventually gene correction
for the betterment of as many human individuals as possible.
It is a pity that Testart and Sele did not address themselves to
such issues instead of raising spectres that may never exist
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