Bad genes for a trucker, pilot, etc

Science
A recent study seems to indicate that there may be a gene behind bad driving. Livescience explains,

"The study involved only 29 individuals, however, 22 without the so-called bad-driving gene and seven with it. The participants drove 15 laps on a simulator that required them to learn the nuances of a track with difficult curves and turns. The researchers measured how well participants stayed on course. The drivers repeated the simulator test four days later.
Participants with this particular gene performed 20 percent worse on the simulation test compared with those without the gene variant. Similar results were found in the follow-up test." http://www.livescience.com/culture/091028-bad-driving-genes.html

Work
Applications in the workplace would abound if the results of this sample study were replicated and the ability to test for the gene were cheap.

Law
However, employer's ability to use this information is constrained by GINA (Genetic Information Nondiscrimination Act)