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Are we on the genetic slippery slope?
No, say doctors specialising in reproductive medicine.
Saviour siblings are just the logical next step
Another barrier to the age of the designer baby for
all has been demolished. A child can now be selected before birth to
become a “saviour sibling” — chosen from a group of embryos solely
because his tissues match those of a sickly older brother or sister. The
argument that invasive testing, involving the removal of one of eight
cells from the three-day embryo, should only be undertaken if the
potential new baby itself is at risk of serious inherited disease has
been swept away. Are we slithering down the slippery slope? Doctors
involved in reproductive medicine deny it. What has happened is simply a
logical piece of tidying up.
The cases of the Hashmis and the Whitakers make the
point clearly. Why should Zain Hashmi be allowed a life-saving sibling,
while Charlie Whitaker is not? It is medical hypocrisy not to permit
both children a chance of life, said Simon Fishel of the Care fertility
unit at the Park Hospital in Nottingham, who is treating the Hashmi
family.
Look at what we do to embryos already — disposing of
them and carrying out research on them is permitted in law, and so is
the termination of pregnancy. Testing them for tissue type and selecting
one embryo over another is a small price for the life of a child.
Ever since the birth of Louise Brown, the first test
tube baby, there have been arguments, Dr Fishel said. “But abuses do not
happen provided there is good regulation and strong licensing [of
fertility clinics]. We will not go down the route of selecting for
trivial or cosmetic characteristics.”
Mohammed Taranissi, the Whitakers' fertility doctor,
who runs the Assisted Reproduction and Gynaecology Centre in London,
said there was a further debate that we should be having now. It is
possible to test embryos for the genes that will cause certain "late
onset" diseases, such as a form of Alzheimer's which can occur in
middle-age and some cancers. Doctors could identify and select embryos
that would have a healthy childhood and youth, but are destined to die
prematurely. "Is this something that we should do? That to me is a very
important issue," said Mr Taranissi.
“This is going to be the future. I don't know myself
what is right and what is wrong. It is something that needs to be put to
a wider audience.”Already he knows of at least seven babies born in the
United States after tests were made on them at embryo stage to ensure
they would not be prey to late-onset diseases.
One woman, whose case was published in the Journal of
the American Medical Association, had the early Alzheimer's gene, which
meant that she would probably not live beyond her mid-30s or early 40s.
The Reproductive Genetics Institute in Chicago retrieved eggs from her
ovaries, fertilised them with her husband's sperm and tested them for
the rare gene APOE-4 that gives those who have it a high probability of
early Alzheimer's. They selected four that did not carry the gene, and
she now has a baby daughter who she can be sure will not inherit the
disease that has devastated her family.
Mr Taranissi has already been approached by somebody
who wants such pre-implantation genetic screening for late-onset
disease. He is inclined to help them, he said. What is the difference
between that and aborting a pregnancy after a positive test for Down's
syndrome? “That seems to be common practice,” he said. “Everybody does
it and nobody questions the ethics of that.”
Simon Fishel goes further. Any fertile couple probably loses hundreds of
embryos without even realising it in a lifetime, he says. They are
conceived but fail to implant in the womb. “If you had two and one of
them was to have serious Alzheimer's disease or breast cancer, what
would you do?” he asked. “I think society should allow you that
freedom.”
Saudi Arabia has recently announced that because there
is so much thalassaemia in the country — the potentially fatal blood
disorder suffered by Zain Hashmi — all couples wanting a child should be
tested and if they are both carriers, they should undergo fertility
treatment so that their embryos can be screened for it. The concern is
partly to do with the financial as well as human cost of treating the
disease. It could happen here. A primary care trust has offered to pay
for a couple at Dr Fishel's clinic to undergo the tests to have a
“saviour sibling” baby. The cost of the treatment of their existing sick
child could run to more than £1m. The cost of bringing a new baby into
the world in order to cure that child through a bone marrow transplant
might be £20,000. “The savings are considerable,” said Dr Fishel.
“In the future we ought to be contemplating whether
the NHS should be funding this procedure.”
Sarah Boseley
22 July 2004
http://www.guardian.co.uk/uk_news/story/0,3604,1266274,00.html
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