GeneWatch UK called today for regulation of human gene tests, in a response to a consultation by the Medicines and Healthcare Regulatory Agency which ends on Friday (1).
A growing number of commercial companies are now marketing genetic tests which claim to predict an individual's risk of common diseases, such as heart disease and cancer (2).
"Doctors can't read Martian and they can't read your genome either", said Dr Helen Wallace, Director of GeneWatch UK. "Most of these tests do not have scientific evidence to back them up. Most gene discoveries have later turned out to be wrong, or else not useful to decide who should take which treatment or advice."
GeneWatch warned that unregulated genetic tests could cause harm by:
- Wrongly identifying those at 'high genetic risk' or wrongly implying that these individuals have more to gain than others by taking particular advice or medication;
- Confusing or undermining public health messages, including advice to quit smoking or eat healthily;
- Encouraging people to take medicines or supplements they do not need, increasing costs and side-effects;
- Creating unnecessary burdens on the National Health Service (NHS), which may be required to provide follow-up advice or tests.
The controversial gene scientists James Watson and Craig Venter are enthusiasts for human gene testing and both have had their whole genomes sequenced, at great expense. However, this hasn't given them any useful information about their health (3). Large new studies have failed to find genes that explain why these diseases run in families and many geneticists now question whether most common diseases will be predictable from our genes (4).
"You share your environment and lifestyle with your family and for most of us this will be more important than our genes", said Dr Wallace, "Gene tests won't help to tackle major health problems such as bad diets, poverty, smoking and pollution".
For further information, contact:
Dr Helen Wallace: 01298-24300 (office), 07903-311584.
Notes for Editors
(1) The consultation considers the MHRA's challenges and priorities for the next five years. GeneWatch UK is calling for a pre-market assessment of all genetic susceptibility tests, including: whether the risk information is reliable and has adequate predictive value (the 'clinical validity' of the test) and whether it is useful to decide who should take the proffered advice (the 'clinical utility' of the test). GeneWatch's submission to the consultation is available on:http://www.genewatch.org/uploads/f03c6d66a9b354535738483c1c3d49e4/MHRA07_1.doc
(2) Examples of five companies that have marketed genetic tests in the UK are included as case studies in GeneWatch UK's submission. None of the tests described received a clinical assessment of any kind before being marketed in the UK.
(3) Most publicity has focused on the APOE gene, which has been linked with increased cholesterol levels and with increased risk of Alzheimer's Disease. However, the effect on cholesterol levels is small and not useful to decide who should take cholesterol-lowering drugs. Most other common genetic variants have not been firmly linked to the risk of any disease, or have only very small effects.
(4) For example, nine genes have now been linked to risk of adult-onset diabetes (type 2 diabetes) but they have such small effects that they do not account for why this condition runs in families. The newly discovered 'obesity gene' (the FTO gene) explains only 1% of the differences in individuals' tendency to become overweight. Although rare mutations in some genes are thought to play an important role in about 5% of breast cancer cases, none of the common genetic variations that have been linked to breast cancer have been confirmed by further studies.