A blood test that could predict an unborn baby's risk of numerous disorders has been devised by scientists.
Using a tiny sample of the mother's blood, researchers can piece together the child's entire genetic code and search its DNA for the flaws behind conditions such as Down' s syndrome and autism. The technique would remove the risk of miscarriage associated with current invasive tests, saving the lives of hundreds of unborn babies each year.
But there are fears that it could be exploited to predict an unborn child's risk of problems from Alzheimer's to cancer and heart attacks, creating worry for parents before their baby has even entered the world.
There are also concerns that parents could abuse the technology to select the 'perfect child', with those not fitting the bill in terms of looks, health or even personality being aborted. Currently, pregnant women thought to be at high risk of having a baby with a condition such as Down's syndrome have the choice of two procedures, amniocentesis and chorionic villus sampling. Both involve putting a needle into the womb and raise the risk of miscarriage.
To remove the risk, research teams around the world are trying to find a way of gleaning genetic information from tiny pieces of foetal DNA that have worked their way into the mother's blood. For instance, NHS-funded researchers at Great Ormond Street Hospital are developing a blood test for Down's syndrome. But the new technique, reported in the journal Science Translational Medicine would allow multiple conditions to be picked up at once.
Using a sample of blood taken from a woman who was 12 weeks pregnant, researchers led by Dr Dennis Lo painstakingly pieced together the entire genetic code of her unborn child and then scanned it for key genetic flaws. They already knew that the child's parents were both carriers of beta-thalassaemia, a life-threatening blood disorder, raising the possibility that the child would have it.
By studying the child's genome, or entire cache of DNA, the researchers were able to reassure the parents that their child would merely carry the illness, rather than suffer from it.
The technique currently costs £125,000 per baby but the price is expected to drop dramatically over time. Dr Lo, of the Chinese University of Hong Kong, said: 'The power of this technology is that by using one test you can see the entire foetal genome.'
But he cautioned that parents might not want to know all the information available and said the test should only be given in conjunction with professional counselling. He said: 'I think the eventual utility of this technique will be to target a number of common genetic disorders that are prevalent in a particular population.' However Dr Helen Wallace of GeneWatch UK said: 'Clearly there are benefits in terms of specific tests that can be done in a safer way.
'But the danger is that the test will be used to predict the risk of a range of diseases and even personality and many of these predictions will be misleading.' Dr Christine Patch, chairman of the British Society for Human Genetics, said: 'While this is a potentially interesting approach that may have benefit for some families with serious genetic disorders, there are many concerns. 'It is too early to apply the technology widely as we are not yet able to interpret many of the results accurately.' Dr David King, of Human Genetics Alert, said: 'The danger of this new method is that it will encourage parental choosiness about minor imperfections, or even cosmetic features.'
Article: 9th December 2010 www.dailymail.co.uk
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