An international survey of predictive genetic testing in children for adult onset conditions

Purpose: Predictive genetic testing is offered to asymptomatic adults even when there is no effective prophylaxis or treatment. Testing of young people in similar circumstances is controversial, and guidelines recommend against it. We sought to document descriptive examples of the occurrence of genetic testing in young people for nonmedical reasons, in the countries where guidelines exist. Methods: Clinical geneticists in the USA, Canada, UK, Australia, and New Zealand were surveyed about the occurrence and outcomes of testing in asymptomatic young people for conditions where no prophylaxis or treatment exists and onset is usually in adulthood. Results: Of 301 responses, details were provided of 49 cases where such testing had occurred. The most common condition tested for was Huntington Disease. In 22 cases (45%), the young person tested was immature, defined as under the age of 14 years. Results were disclosed to only two immature minors and in three cases parents experienced clinically significant anxiety related to how they would pass on information to their gene positive child. In 27 cases (55%), the young person tested was mature. Results were disclosed to 26 mature minors and it was reported that two individuals experienced an adverse event. Consistent follow-up did not take place and findings represent the minimum frequency of adverse events. The majority of respondents agree with existing guidelines but many believe each case must be considered individually. Conclusion: Clinicians agree with existing guidelines regarding predictive testing in young people, but choose to provide tests for nonmedical reasons in specific cases.