One of the tricky things about using genetic tests in medicine is whether knowledge of a particular gene variation is sufficient to offer specific medical advice.
Two different screening programs affecting college students this fall underscore some of the complications in the emerging world of personalized medicine.
The journey to self-awareness might have taken on different meaning for incoming freshmen this fall at the University of California, Berkeley, if state authorities hadn't intervened to restrict how tests for several genetic traits could be done.
Initially, university officials had planned to share results of the tests with individual students who had voluntarily submitted saliva samples for screening of three genetic traits related to their ability to metabolize alcohol, lactose and folic acid. Along with the individualized results would have come information about how the students might want to adjust their diets to accommodate their genetic predisposition.
All of this was to be something like a class orientation project, aimed at educating the first-year students and generating discussion about genetic tests, personalized medicine and related topics -- and perhaps improving the health among some of the 5,500 new enrollees.
Along with national and on-campus clamor from bioethics experts concerned about privacy and other issues, the project drew the attention of the California Department of Public Health.
Officials concluded, among other things, that the " Bring Your Genes to Cal" program amounted to an unauthorized medical test on each student -- state law says doctors have to order such tests -- and then they must be done by a licensed clinical lab, which Cal's facilities are not.
So, instead, the 1,000 or so samples actually submitted will be used only to aggregate data about the genetic make-up of the class of 2014, with no individual results, to support several ongoing research projects.
Medicos have a long history of proposing mass health screening for entire classes or school systems, and tests for some conditions that particularly affect learning, such as vision and hearing, are mandatory just about everywhere.
Other proposals, from head-lice exams to screening for high cholesterol or hypertension to mental-health problems, have been less universally adopted, often because authorities don't feel the collective health benefits justify the time or expense.
But another collegiate screening program starting this fall was actually set up in part to settle a lawsuit filed by the parents of a Rice University freshman football player who died after collapsing during practice in 2006.
Under terms of the settlement, the NCAA is requiring all incoming student athletes at the nation's largest colleges (Division I) to be screened for sickle-cell trait, a condition in which one gene codes to form normal red blood cells, the other to form cells that are fragile and irregularly shaped.
While people with sickle-cell disease carry two genes that code for irregular cells and have lifelong health problems, most people with sickle-cell trait have no symptoms, except when they're engaged in rigorous exercise.
During intense training, the red blood cells can change shape and actually clog blood vessels and cut off blood and oxygen flow to the heart.
Sickle-cell trait has been linked to at least nine of 21 deaths among U.S. collegiate football players since 2000. The trait is present in about one in 10 African-Americans and occurs rarely in whites. It can be identified with a $5 blood test.
While infants are supposed to be screened for the trait at birth, many students may reach college unaware of the results. So, the NCAA rule requires freshmen and transfer athletes to either provide proof they've been tested for sickle trait, get the test done before starting training or sign a waiver declining to have the test done while absolving the NCAA and their college of liability -- an option offered in case students fear future genetic discrimination.
However, the NCAA specifically states that carrying sickle trait should not bar any athlete from taking part in any sport. The program also includes widespread distribution of pamphlets and a video about the condition, along with other efforts to educate athletes about the condition and how to ease into training gradually if they have it.