Genetic testing does not reveal if you have a disease. It can only show that you are predisposed to getting an ailment. Barring a worker because they may one day develop a fatal disease is like throwing someone in jail because they may someday steal a car. There is no certainty that the disease will ever develop just as there is no way to profile who may become a thief. According to the American Medical Association (AMA), "Genetic tests alone do not have sufficient predictive value to be relied upon..." ("Genetic Testing"). Our limited knowledge of the complex interactions of numerous genes and our environment makes this new science little more than guesswork.
If employers begin guessing who may have a genetic marker for a physical ailment, it won't be long before they look at brain scans for a predisposition of a personality trait. Medical ethics would dictate that, "Genetic privacy, like medical privacy in general, involves notions of the dignity and integrity of the individual" (Bereano).