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| Courtesy: The Sun |
TheHuman Fertilization and Embryology Authority (HFEA) announced on
Thursday that it is ready to give licenses to clinics for the controversial ‘Three Parent ‘IVF procedures.
HFEA chair Sally Cheshire called it “historic
and important" decision to license the treatment, naming it "a world
first". She further added “Today’s historic decision means that parents at
very high risk of having a child with a life-threatening mitochondrial disease
may soon have the chance of a healthy, genetically-related child. This is life-changing
for those families. We feel now is the right time to carefully introduce this
new treatment in the limited circumstances recommended by the panel.”
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| courtesy: You Tube |
In response to lobbying by MuscularDystrophy UK, lawmakers voted in favor of this pioneering technique in
February, 2015 allowing the use of DNA
from three people to prevent children being born with certain fatal genetic
diseases.
The first child born with this technique
is expected to take birth at the end of 2017.
The procedure has been developed by
scientists at Newcastle University.
Advocates of the new procedure say around 2,500 women could benefit from mitochondrial donation in Britain, equating to around 150 births a year as one in 200 children born in the UK have some form of mitochondrial disorder.
Advocates of the new procedure say around 2,500 women could benefit from mitochondrial donation in Britain, equating to around 150 births a year as one in 200 children born in the UK have some form of mitochondrial disorder.
Prof Doug
Turnbull, Professor
of Neurology and director of the Wellcome Centre for Mitochondrial Research Newcastle
University plans to treat 25 carefully selected patients each year.
Mutations in mitochondrial DNA are maternally inherited and are responsible for causing many debilitating disorders without definitive treatment. Diseases of the mitochondria appear to cause the most damage to cells of the brain, heart, liver, skeletal muscles, kidney and the endocrine and respiratory systems.
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| Image courtesy:The telegraph |
Mitochondrial replacement therapy, has
been shown to be a novel technology in minimizing mutated mtDNA transmission
from oocytes to pre-implantation embryos.
In this technique, the nucleus of an
affected woman's extracted egg is removed and is put into the enucleated egg of
another woman, which contains her mitochondria. The child would thus be
genetically related to three people, which is why the media often refers to
"three-parent babies" or "three-parent in vitro
fertilization."
These techniques have been referred to with several terms, including "mitochondria replacement," "mitochondrial manipulation," "oocyte modification," "three-person embryos," "three-parent babies," and "nuclear genome transfer" (the most technically accurate).
The procedure can be carried out in
one of the two ways.
1) maternal spindle transfer (MST).
2) pronuclear transfer (PNT).
1) maternal spindle transfer (MST).
2) pronuclear transfer (PNT).
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| 2-ways of the three-parent in vitro fertilization |
The simpler of the two is called
maternal spindle transfer (MST). First, doctors use standard IVF treatment to
collect eggs from the mother. They then remove the nucleus from one of the
mother’s eggs and transfer it into a healthy donor egg that has had its own
nucleus removed. The reconstituted egg holds all the mother’s healthy nuclear
DNA, or 99.8% of her genes, plus the donor’s healthy mitochondria. This egg is
then fertilised with the father’s sperm and the embryo is implanted into the
woman like any other IVF embryo.
The second procedure is very similar. In pronuclear transfer (PNT), both mother and donor eggs are fertilised with the father’s sperm. Before the eggs have time to split into early-stage embryos, the chromosomes inside them are removed. Those from the donor egg are discarded, and replaced with the chromosomes from the mother’s egg. The resulting egg is fertilised and ready to grow into an embryo in the mother’s womb.
The second procedure is very similar. In pronuclear transfer (PNT), both mother and donor eggs are fertilised with the father’s sperm. Before the eggs have time to split into early-stage embryos, the chromosomes inside them are removed. Those from the donor egg are discarded, and replaced with the chromosomes from the mother’s egg. The resulting egg is fertilised and ready to grow into an embryo in the mother’s womb.
Robert
Meadowcroft, CEO of Muscular Dystrophy UK, responds: “Today, this historic
decision will open the door to the first licensed treatments being offered to
eligible women affected by mitochondrial disease.
Families
have, understandably, had to wait through years of thorough ethical, safety and
public reviews. We know of many women who have faced heartache and
tragedy, and the sorrow of stillbirths, while trying to start their own family,
and this decision gives them new hope and choice for the first time.”
However, many
have opposed the approval of the 3-parent baby. Christian bioethics
campaigner James Mildred said: "This is a dangerous step in completely the
wrong direction." Another critic commented that it brings us a step closer
to designer babies.
SOURCES:
The
mirror,UK
Human
Fertilisation and Embryology Authority (HFEA)
The Guardian
British
Fertility Society
Muscular
Dystrophy UK
