Take a Family Approach to Genetic Testing

Knowing whether you’re a genetic carrier for a disease can be invaluable. A patient who learns she’s at heightened risk for breast cancer, for example, may opt for more frequent mammograms or have a preventative mastectomy, potentially adding many happy and healthy years to her life.

The US Preventive Services Task Force currently advises that individuals who have a family history of a disease should consider genetic testing. But taking a family approach to testing, applying one patient’s results to understand the risks to other family members, could generate comparable health benefits at less cost, suggests research by Chicago Booth’s Dan Adelman and Kanix Wang.

In theory, everyone could be tested for a wide array of potential diseases. But that’s a cost-prohibitive proposition, so what’s the optimal testing system? The researchers studied the issue by simulating the testing of 5 million people for the BRCA1 and BRCA2 genes, which are associated with an increased risk of developing breast cancer. The algorithm Adelman and Wang developed can determine who needs to be tested and can rule out the possibility that some family members are at risk on the basis of others’ results.

At $750 per test, an optimal family-testing policy involving these genes alone would add nearly 300,000 quality-adjusted life years to at-risk people over their lifetimes, 3,000 more QALYs than would be added by testing all people who meet the USPSTF’s guidelines, for $500 million less. A QALY is a measure used by economists to tally the quality and quantity of a life, and one QALY equates to a year of perfect health.