Thursday, July 3, 2008

Choosing and Selecting Your Embryos

This headline from the Telegraph caught my attention.

'Designer baby' to be free from breast cancer
By Joanna Corrigan
Last Updated: 7:17PM BST 29/06/2008
A British woman has made history by conceiving the country's first "designer baby" guaranteed to be free from hereditary breast cancer. Using controversial screening techniques, doctors rejected six embryos which tested positive for the cancer gene in favour of "healthy" ones to ensure the child would not contract the disease.

Actually it is not a 'designer baby' but more of a 'selected baby.' There was no designing involved and no modification of the genetic code. By a process named preimplantation diagnosis (PGD), embryos are tested for genetic defects. Those who were detected positive were rejected. In this case, it was for the gene causing breast cancer. Only those embryos who are tested free from these genes are implanted into their mother's womb.

The article continues,

If the British couple had conceived a daughter from an embryo containing the hereditary gene, called BRCA-1, the odds of her developing breast cancer would have been between 50 and 85 per cent. More then 2,000 breast cancer cases diagnosed in Britain each year are thought to be caused by either the BRCA-1 of BRCA-2 genes, which can both be detected in embryos. Many women who test positive for either of the genes go through a mastectomy to avoid developing the disease later in life.

Many people are already aborting their foetuses with Down's syndrome. However, this normally done during the first 3 months of pregnancy when amniotic fluid drawn from the womb were examined and the foetus was diagnose to have the condition. In these cases, it is obvious that these foetuses are already human beings.

Now with preimplantation diagnosis (PGD), the examination is done before the embryos or fertilised eggs are implanted into the womb. These embryos are just a mass of 4-8 cells. Will it be acceptable to reject them? They are not viable outside a womb. Are these embryos the same as a foetus who has been inside a mother's womb for at least 2 months? The former is a mass of cells while the later has began to develop recognisable head, arms and legs.

The question here is not about designer babies in which babies are selected for intelligence and looks. That is still a long way off. The question is whether preimplantation diagnosis should be allowed. Arguing from the point of compassion, it will prevent a lot of suffering in these affected embryos. Is that a good enough reason?

read rest of Telegraph's article

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