A new study published in Genetic Epidemiology has reported that genotyping provides no additional medical benefit over standard predictive information such as medical and family history.
Researchers recruited over 3000 recipients of the Health Compass service from direct-to-consumer (DTC) genetic test provider Navigenics, which provides an estimate of risk for fifteen conditions. Study participants provided self-reported personal medical and family history information, which was used to predict risk, and the two measures of lifetime disease risk were then compared.
For five conditions with ‘relatively high heritability’ the researchers found significant association between the genetic and medical history risk estimates. They concluded that the genetic risk information was as accurate as traditional risk prediction for these conditions, though it did not offer any additional benefit. For the other ten conditions, there may be no such association, or it may be that too few people were included in the analysis to detect such links, since relatively few had family or personal histories of the diseases.
Of note, recent moves to prohibit DTC genetic testing in the US (see previous news) have led Navigenics to switch to marketing services to health care providers and funders instead.
Comment: This study suggests that DTC predictive genetic testing does not offer additional medical benefits compared with traditional risk assessments, unless of course there is no family history information available. However, at the same time it shows that genetic data can have genuine predictive value. Do legal prohibitions of such services protect consumers from dangerous harms, or from wasting their money – or merely restrict their choices with respect to health information?