Genetic testing is a relatively new process. A service that used to cost thousands of dollars can now be accomplished for a cheek swab and $200. But what can genetic testing really tell you? And where do the results of a genetic test fall short of a diagnosis? Genetic testing can provide a person with important knowledge about their body, such as their likelihood to get a disease or allergies to a food. But it’s important to know that the results of genetic test can only tell so much.