Wait a minute, isn't that illegal? The use of such tests by employers (and insurance companies) was the subject of last year's Genetic Information Nondiscrimination Act (GINA). That took care of the problem before it became a major issue, most people thought. But as so often happens, reality presents different questions than anticipated.

On July 16th, CNN-SI reported that the Yankees had voided a contract with a youth from the Dominican Republic who had lied about his age and name, and been caught by a DNA test. It's not clear exactly what happened in this case, but prospects frequently try to shave a year or two off their ages, sometimes by "borrowing" someone else's birth certificate. Testing parents and siblings, as well as candidates, is one way to confirm or disprove identity.

The incentive to cheat is huge. Even a minor-league contract in MLB pays a minimum of $65,000 after the first year, and in the majors it's $400,000, not to mention signing bonuses: The kid who was caught would have received $850,000 up front. That's good money anywhere -- and people in the Dominican Republic make about one-sixth what Americans do. So some people look on these identity tests as reasonable. And MLB may have found some wiggle room in GINA; the law, which comes into effect this fall, may not apply to overseas recruitment.

The New York Times followed up, and revealed that clubs have been using DNA tests for a while. At least one prospect also had to provide samples of his blood, urine and feces, and both he and his sister had bone scans too. All of this is supposedly to confirm identity, but what else can -- or might -- be found in the samples?

Predictive tests for athletic ability have been discussed for some years now. Slugging strength and base-stealing speed call for different sets of physical abilities, but in theory it's possible that an adolescent's final development could be predicted in part from his genetic make-up. Picking prospects is notoriously hard, so any edge would be particularly valuable.

But then, the opposite holds true, also. The growth of direct-to-consumer testing services has largely been focused on predicting disease, including late-onset disorders. And here's a rich baseball irony: Lou Gehrig, the iron horse, ultimately suffered from Amyotrophic lateral sclerosis (ALS), which was and is still often called Lou Gehrig's disease. ALS ended his outstanding career and killed him two years later. Would a modern prospect at even slight risk for ALS get a chance?

Kathy Hudson of the Genetics and Public Policy Center told the Times:

"DNA contains a host of information about risks for future diseases that prospective employers might be interested in discovering and considering. The point of GINA was to remove the temptation and prohibit employers from asking or receiving genetic information."

Jeremy Gruber of the Council for Responsible Genetics added: "There are many instances where employers have acquired information for one reason and used it for another."

Many of us are skeptical about the use of genetic predictive tests, but it's all too easy to imagine abuse by management.

And then there is the bizarre, science-fiction scenario of ambitious, adolescent ballplayers faking their genetic identity -- not just borrowing a birth certificate but smuggling samples into the lab. The movie GATTACA provided a primer on that in 1997.

The incentive to cheat doesn't operate just for players. Polling shows that a large majority of Americans believe that "not enough was done to prevent players from using steroids." It's easy to see why this should be so -- Major League Baseball is a huge business that is ultimately dependent on a relatively small number of stars. The scandal-plagued Alex Rodriguez makes $33 million but the New York Yankees are worth $1.5 billion. No wonder baseball is a case study for dubious technologies.