April 24, 2024

The other controversy about genetic tests

The hot water into which 23andme has landed is just one of many simmering controversies about genetic testing.

The hot water into which 23andme has landed is just one of many simmering controversies about genetic testing. Earlier this year the American College of Medical Genetics released new guidelines about how much of the “incidental” information from a genetic test should be given to patients. This is information gleaned from a test for one genetic condition which is not related to it but which might be relevant to a patient’s health.

For example, a test for hereditary hair loss might reveal that you have a gene strongly correlated with an aggressive cancer. Should the doctor tell you? Do you have a right not to know this information?

The American College of Medical Genetics and Genomics (ACMG) made an abrupt change of policy earlier this year and decided that it would be unethical not to disclose all the incidental findings, even if a patient does not want to know. In other words, the patient’s autonomy comes second.

“We recognize that this may be seen to violate existing ethical norms regarding the patient’s autonomy and ‘right not to know’ genetic risk information,” wrote the authors of the ACMG recommendations. “However … we felt that clinicians and laboratory personnel have a fiduciary duty to prevent harm by warning patients and their families about certain incidental findings and that this principle supersedes concerns about autonomy.”

Is this a big deal? Why shouldn’t patients get as much information as possible?

It is a big deal: a commentary in JAMA declared that it had “profound implications for countless physicians and their patients”. The policy of the ACMG is that every genetic test evaluates 57 genes, so abundant “incidental” information is harvested. One of the flashpoints is how this affects children and adolescents. Previously, genetic counsellors could withhold information about conditions which might affect health – but might not, too. The tests can return false positives and could lead to needless anxiety, expensive and unnecessary screening tests and even prophylactic surgery.

Three prominent American bioethicists wrote in Science that “Starting down the path of unconsented testing and reporting in clinical genomics leads to grave difficulties, and should not be done without more careful analysis.”

Michael Cook
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genetic tests
incidental findings