Connexin 30 (GJB6) deletion as a cause of a false positive sweat test result.

Summary: Doctors use a "sweat test" to check for a disease called cystic fibrosis. Sometimes, the test says a person has the disease when they really don't. This is called a "false positive." In this study, doctors found a new reason for this mistake. Three patients who were deaf because of a missing piece of DNA (called Connexin 30) all had abnormal sweat tests. Two of them even got very sick from losing too much salt and water. The doctors learned that this missing DNA changes how sweat glands work, causing a false alarm on the test.