The Three Parent Embryo
The House of Commons in the United Kingdom passed a
historic vote to allow a new genetic technique called mitochondrial
replacement or ‘3 person in-vitro fertilization.’ There were 382 ayes
and 128 nays in the vote on 3rd February 2015 which was closely
watched by researchers and scientists all over the globe. The House of
Lords is still to vote on the issue, and then it will go for further
approval to the UK fertility regulator – The Human Fertility and
Embryology Authority (HFEA). The technique will help women who have
children with mitochondrial disorders. Around 1 in 5000 children are
born with diseases caused by mitochondrial mutations.
There are two techniques which will prevent children
from inheriting their mother’s mitochondria. In Pronuclear transfer, the
mother’s egg is fertilized in vitro by the father’s sperm. The
pronucleus of the fertilized egg is then transferred into a donor egg
whose pronucleus has been removed. In the other technique called
Maternal spindle transfer, the spindle of chromosomes is removed from
the unfertilized egg and introduced into a donor egg which is
subsequently fertilized in vitro by the father’s sperm.
The technique is still banned in the US, but the UK
vote is likely to change the tide in favor in many countries. UK was the
first country to approve in vitro fertilization in 1978 which has led to
the birth of several million babies since. Those against mitochondrial
replacement fear that the law will open up doors to further genetic
manipulation for desired traits in offspring i.e. ‘designer babies.’
Nobel laureates and many of UK’s famous scientists have worked hard to
create public awareness and support for mitochondrial replacement over
the last year and to educate their parliamentarians. But lingering
worries remain. Will fragments of residual mutated mitochondrial DNA be
inadvertent stowaways and cause health problems for future generations
of kids? In animal studies, non human primates born by this technique
have survived to adulthood, but will their future generations be
healthy? In the brave new world of genetic manipulation, caution and
care is paramount. (Nature 3 February 2015)
Synthetic Antibody Mimics
David Spiegel of Yale University went to medical
school to become a psychiatrist. On the way he decided to do a PhD in
Organic Chemistry. He is in now in the news because of a remarkable
achievement. He and his team have developed the world’s first synthetic
molecules which mimic antibodies. Normally antibodies we use in clinical
medicine are large proteins which are difficult and expensive to
produce, denature easily, and can trigger unwanted immune responses.
Synthetic antibody mimics can be produced in the laboratory, are one
twentieth the size, and are unlikely to trigger immune reactions. Their
greatest advantage is that they can be given orally.
The history of antibody research was spawned by Paul
Erlich in the 19th century when he stated that the body defends itself
against pathogens by forming antitoxins. His group worked on forming
antitoxins for various diseases like trypanosomiasis. Later antibody
research split into two groups. One group developed monoclonal
antibodies that are now widely used in clinical medicine. The other
group started working on synthetic antibody mimics. Spiegels group has
developed synthetic antibody mimics against prostrate cancer, HIV and
bacterial triggers for autoimmune diseases. The work is still at the
level of the petri dish. A mouse model is still being developed which
will then be followed by human studies. These new drugs will change the
landscape of medicine and drastically bring down the cost of antibodies
in medicine. (Scientific American 9 February 2015)
National Deworming Day
The Health Minister of India has declared 10th February as the
National Deworming Day. About 24 crore children are estimated to receive
the medicine in February 2015 itself. Children below two years will
receive half a tablet of albendazole, and those above two years will
receive a full tablet. Children between 1-19 years are being targeted
and will receive the medicine in anganwadis and government
schools. Stringent adverse event protocols have been put in place with
training of teachers, anganwadi workers and health officials. (The Hindu
10 February 2015).