Direct to Consumer Genetic Testing in Denmark—public Knowledge, Use, and Attitudes

Direct to consumer genetic testing (DTC-GT) is offered by commercial companies, but the use in the general population has only been sparsely investigated. A questionnaire was sent to 2013 representative Danish citizens asking about their awareness and use of DTC-GT. Individuals who had undergone a genetic test were interviewed to determine if the results had been understood correctly. A pilot study with 2469 questionnaires was performed before this study. In total, 45.4% of the individuals ( n = 913/2013) had knowledge about DTC-GT and 2.5% ( n = (18 + 5)/913) previously had a genetic test by a private company and 5.8% through the public health care system ( n = (48 + 5)/913). Curiosity about own genetic information was the most frequent motivation (40.9%, n = 9/22) as well as knowledge of ancestry (36.4%, n = 8/22) and advice about lifestyle, exercise, or diet (36.4%, n = 8/22). Test of own disease risk was given as a reason in 27.3% ( n = 6/22) and seeking possible explanation of specific symptoms in 13.6% ( n = 3/22). 50% ( n = 11/22) answered that they had become concerned after the test, and 17.4% ( n = 4/23) had consulted their GP. Interviews in a subset of respondents from the pilot study revealed problems with understanding the results. One problem was how to interpret the genetic test results with respect to individual risk for a disease. For example, the difference between disease causing genetic variants in monogenetic diseases versus statistical risks by SNPs in multifactorial diseases was not understood by the respondents.