Direct-to-consumer genetic tests under fire from geneticists
Amsterdam – Two studies presented at the annual conference of the European Society of Human Genetics yesterday show that common Direct-to-consumer (DTC) genetic tests give inaccurate predictions of disease risks and thus European geneticists want to ban most of them. At the conference, Dutch researchers under Rachel Kalf from University Medical Centre, Rotterdam, presented an analysis of the risk predictions for eight common multi-factorial diseases offered by the DTC companies deCODEme (Iceland) and 23andMe (USA) that showed quantitatively that the predictions were inaccurate and exaggerated and did not take non-genetic disease risk factors into account.
In the second study, Dr. Heidi Howard from the University of Leuven, Belgium, and her colleague Professor Pascal Borry reported the results of the first survey of a representative sample of clinical geneticists from 28 countries across Europe on their experience of and attitudes to DTC genetic testing. According to the poll, 69% of respondents felt that prenatal gender tests should be legally banned, and 63% wanted to prohibit whole genome scans carried out by DTC companies, Additionally, 90% of respondents felt that a pre-symptomatic test - predicting if an asymptomatic person had a very high probability of developing a condition - should not be allowed without face-to-face medical supervision; 93% felt the same for a predictive test for a condition that has a penetrance of 50 – 60%; 79% for a carrier test for homozygous monogenic disorders, such as sickle-cell anaemia; and 72% for a predictive test for a condition that increased or decreased a person's risk of developing it by 4% when compared to the general population. At the moment, DTC genetic tests reach the market without having undergone any form of regulation. Currently only a few European countries, for example France and Switzerland, have legislation that states that genetic tests can only be accessed via individual medical supervision.