Wednesday, 20 March 2013

Biomedical Ethics: Evolution of Science and Technology

Designer Babies/Pre-implantation Genetic Diagnosis

With the advanced technology nowadays, scientists have developed a method to screen human embryos for genetic disorders. This method is known as Pre-implantation Genetic Diagnosis, or simply, PGD.

PGD is a technique that enables people with a specific inherited condition in their family to avoid passing it on to their children. It involves screening the genes of embryos created through in-vitro fertilisation for this genetic condition.


How does PGD work? (as shown on website of  Human Fertilisation Embyology Authority of UK)

The procedure for PGD is likely to be as follows:

Step 1-One undergoes normal IVF treatment to collect and fertilise her eggs.

Step 2-The embryo is grown in the laboratory for 2-3 days until the cells have divided and the embryo consists of around eight cells.
Step 3-A trained embryologist removes one or two of the cells (blastomeres) from the embryo.
Step 4-The cells are tested to see if the embryo from which they were removed contains the gene that causes the genetic condition in the family.
Step 5-Embryos unaffected by the condition are transferred to the womb to allow them to develop.
Step 6-Any suitable remaining unaffected embryos can be frozen for later use. Those embryos that are affected by the condition are allowed to perish.
Step 7-About two weeks after the embryo transfer, the woman is given a pregnancy blood test.
Removal of cells (blastomeres) from embryo




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Could you envision a world without genetic diseases, where parents could control their child’s height, muscle strength, eye color, personality, and even intelligence? Some might consider this a tempting endeavor while others see it as a horrifying science fiction novel turning into reality. The topic of the most recent Intelligence Squared U.S. debate, Prohibit Genetically Engineered Babies, sparked a heated discussion on whether or not this science should be banned. Even if the science were perfected, would human genetic enhancement be considered morally wrong?
The team arguing for the motion to prohibit genetically engineered babies was Sheldon Krimsky, a professor at Tufts University and chair of the Council for Responsible Genomics, and Robert Winston, professor at Imperial College London. Arguing against the motion was Nita Farahany, professor at Duke University, and Lee Silver, professor at Princeton University.
Krimsky argued that there are less ethically controversial and more dependable methods of preventing the birth of a child with a severe genetic abnormality by using prenatal embryo diagnosis, with the exception of mitochondrial disease.
“The idea of genetic enhancement grows out of a eugenic ideology that human perfection can be directed by genetics,” said Krimsky. “The danger is not so much that it will work, but as a myth, it will have social power that can be used by those who have wealth and resources to make others believe that to be prenatally genetically modified makes you better.”
Arguing against the ban, Farahany explained how women with a high level of mitochondrial abnormality will be able to have their own healthy genetic children through genetic engineering of the babies through two techniques: pronuclear transfer and maternal spindle transfer that safely eliminate the risk of these diseases. She raised the question, what distances will women afflicted by mitochondrial disease travel to safeguard their children? “Reproductive tourism is already rampant, where women and couples are traveling to foreign countries to gain access to reproductive technologies banned in their own countries,” said Farahany.

Website References: 
http://www.hfea.gov.uk/preimplantation-genetic-diagnosis.html
http://www.genengnews.com/gen-news-highlights/designer-babies-debate-heats-up/81247994/
Research posted by: Sherissa Chua (29)

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