Don’t play poker with your genes
‘Acting on the knowledge of a single (or even a few) gene variants is similar to betting all your money on a poker hand when you’ve only seen one card. You don’t know what hand genetic factors has dealt you, nor what effects your environment will have, and here, instead of 5 cards, there are over 20,000 genes and many thousands of environmental factors. And the effect of one gene may be cancelled out by the effect of lifestyle, family history or by the presence of other, protective genes. Many of us carry faulty genes without them ever causing disease.’
Sense About Science. Making sense of testing: a guide to why scans and other health tests for well people aren’t always a good idea. London: Sense About Science 2008, p7.
Read more in: Genetic tests: sometimes useful, often dodgy.