for National Geographic News
"I have super powers," a girl named Megan whispers to her doctor on a recent episode of the TV show Grey's Anatomy.
That's her explanation for how she's able to withstand nasty gashes and being hit with a baseball bat—all without feeling any pain.
Megan actually has a rare genetic disorder that renders her insensitive to pain. And although she is a fictional character, her problem is real.
Across the world about a few hundred people suffer from one of a variety of diseases that make them completely unable to feel pain from the time they're born.
Now a new form of this disorder has been recognized among people from northern Pakistan, and scientists have tracked down the mutated gene responsible for the condition.
Their study, published today in the journal Nature, could help researchers gain a better understanding of how pain works and may help them develop new painkillers with fewer side effects.
(Related news: "Toxic Snail Venoms Yielding New Painkillers, Drugs" (June 14, 2005)
Among people who are born without pain sensations, the classic case of the disorder is called congenital insensitivity to pain with anhidrosis (lack of sweating).
These patients usually have a variety of physical ailments, including slight mental retardation.
Only a handful of sufferers are like the TV character Megan, without major symptoms beyond a loss of pain.
Researchers discovered the latest version of the disorder when they spotted a young street performer in Pakistan.
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