Direct-to-consumer genetic testing with third party interpretation: beware of spurious results

Direct-to-consumer (DTC) genetic tests aim to provide insights into issues as varied as ancestry, nutrition, athletic ability and child talent, and some also report on disease risks. DTC companies tend to present their tests as uniformly beneficial, but the quality of the information they provide can be doubtful. Tests often invite people to step between territories, from the consumer in search of ‘fun’ information to potential patient, and the boundaries between these roles become even murkier when individuals explore the raw data from their DTC tests using third-party interpretation websites. We discuss two composite cases from U.K. genetics centres where patients used third party interpretation services to analyse raw data from DTC genetic tests. They then presented to NHS clinical services requesting interventions based on the disease-associated variants found, only to find that these variants were not actually present: their ‘pathogenic results’ were spurious. We highlight the risk of false positives (as well as false negatives) from DTC genetic tests, and discuss whether these cases represent the start of a worrying trend, where publicly funded clinicians and clinical scientists increasingly need to spend time and money investigating genetic results of dubious validity.