Predicting the Future of Genetics

Dealing With Risk

The usefulness of genetic testing varies by specialty and circumstance. It has perhaps gained the most traction (though not without sociopolitical controversy) in the field of obstetrics. Knowing what genes might be passed to a fetus or what conditions the child is likely to have provides prospective parents with options—whether that means terminating the pregnancy or preparing to raise a child with special needs.

"Certainly if a couple is thinking about becoming pregnant, genetic testing is warranted," McCaffrey says. Screening for Down syndrome is routine in the United States, but she notes, "[The test] is very inaccurate. So we get them all worried and then do amniocentesis. It would be better to do a pre-pregnancy genetic screen than to wait until their fourth month of pregnancy and do the alpha-fetoprotein test."

Another area in which genetic screening is prominent, though plagued by controversy, is breast cancer. Preventive measures are available, but some question whether the current options are too extreme or whether women might regret, say, undergoing prophylactic mastectomy if new treatments become available before their risk would ever reach the highest category.

"That's one end of the spectrum," McCaffrey says. "But if you know you have BRCA2, you might be more vigilant in testing for ovarian cancer. That's the biggest thing we can do, overall—if you have a patient who has the gene for a certain disease, you're going to be much more vigilant at monitoring them."

Again, genetic information has to be put in context. Having a particular gene does occasionally guarantee you will develop a disease (eg, Huntington's disease). But in most cases, it's more of a tip-off that something might happen sometime in the future. Rackover, for example, was told he had an increased risk for Crohn's disease, but since he was already 61 at the time of testing and has never had any symptoms, it wasn't something that especially concerned him. Someone less informed about the concept of risk, however, might have panicked and started demanding treatment for a condition he doesn't have and may never develop.

And then there are cases such as Huntington's disease, for which nothing can be done. A patient who discovers he or she has one of the associated genes might make different life decisions, but there is no prevention plan that can be put into action. This also raises the conundrum of sharing the news with relatives—who may or may not want to know, who may or may not want to consider their own risk. We tend to think of genes as a personal matter, but they're not. We share them with others.