Genetic tests to assess disease risk are proliferating but many are a waste of money and tell people little more than they would know from studying family history, medical experts said.
A host of companies now offer tests, typically costing hundreds of dollars, to calculate genetic risks for common conditions like cancer, diabetes and heart disease that involve multiple genes.
But Christine Patch, a genetic counsellor at Guy's and St Thomas' NHS Foundation Trust and a member of Britain's Human Genetics Commission, said most had little clinical relevance.
"My message is you are wasting your money," she told a news briefing.
Some tests give false hope
People also faced either unnecessary anxiety, if a test showed a raised risk, or false reassurance, if they were given an all-clear, she added.
Paul Pharoah, from the Cancer Research UK Department of Oncology at Cambridge University, said real strides were being made in science but researchers still did not know enough about enough genes for tests to be really useful.
Scientists have linked a growing number of genes to common diseases but these genes typically interact in a complicated fashion and their ultimate effect is influenced by environmental factors in ways that are poorly understood.
The field of genetic testing has traditionally involved looking at a few specific genes.
More companies joining
But that is changing with the launch of new genome-wide searches that promise a brave new world of targeted healthcare, in which each individual can see his or her genetic code.
Two companies, Iceland's Decode Genetics Inc and 23andMe, a US firm funded by Google Inc, launched rival services earlier this month offering people a glimpse of their entire genome for just under $1 000.
A third unlisted US company, Navigenics, is set to join the fray shortly.
Stuart Hogarth of the Institute for Science and Society at University of Nottingham said the entry of these new players, with substantial financial backing, highlighted the growing commercialisation of the gene testing business.
Business coming before science
The risk, however, was that business development plans were running ahead of science, while regulators were left floundering with an inadequate system of oversight.
"We still do not have a regulatory framework that can control this burgeoning field," Hogarth said.
"In the absence of such a regulatory system, we are in severe danger of losing public confidence in what is a very promising and very exciting field of science."
The field of genetic testing has been revolutionised not only by scientific breakthroughs but also by the development of smart chips from the likes of Affymetrix Inc and Illumina Inc, which can test DNA at various sites along a person's genome. – (Reuters)
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