Consumer genetic tests flawed: scientists

Genetic tests sold directly to consumers that claim to predict risk of disease should be banned, say researchers who studied the products.

The scientists examined tests provided by two companies, deCODEme in Iceland and 23andMe in the U.S.

On Tuesday, Rachel Kalf from the department of epidemiology at Erasmus University Medical Centre, Rotterdam, The Netherlands, told the annual conference of the European Society of Human Genetics that tests sometimes show a consumer is at increased risk even though the individual is far more likely not to develop a disease than to develop it. 

For example, "this difference in disease risk is too small to be of relevance," Prof. Cecile Janssens said of the companies' Type 2 diabetes results.

The researchers said genetic tests have gone to market without regulation, and such tests should be accompanied by genetic counselling.

The researchers criticized the companies for what they called an exaggerated and inaccurate message about the connection between genetic information and disease. The companies may leave out how factors such as diet, environment, exercise and smoking often have a much stronger impact on disease, Janssens said.

A second study by Dr. Heidi Howard from the University of Leuven, Belgium, and her colleague Professor Pascal Borry surveyed clinical geneticists about banning prenatal genetic tests.

"Better regulation is needed at the level of market introduction of these tests," said Borry.

Currently, only a few European countries such as France and Switzerland say medical supervision is needed to access genetic tests.

Borry acknowledged the approach may be considered too paternalistic, but without better pre-market controls he says it could be a useful way to respond to some of the testing concerns.

Kari Stefansson, the chief executive of deCODEme, said the Dutch team misinterpreted computer models in coming to its findings, The Guardian reported.

23andMe told the newspaper it takes extensive measures to provide accuracy and to highlight context.