Wednesday, March 28, 2007

Surviving the perils of a life without pain

Surviving the perils of a life without pain

A disorder that prevents people from feeling injuries can be dangerous. But their gene may give others hope.

Globe and Mail

No good parent wishes pain upon her child, but Verna Mahar wished it for two of her sons -- the eldest, Owen, most of all.

From the time he was a baby he was a roughhouser -- banging his head against walls and table corners without a whimper. When he was a toddler he'd bite his fingers to the bone unless she made him wear mittens indoors. His lips she could do nothing about: Owen chewed them happily until they bled.

"My husband and I didn't understand it. He didn't cry for nothing," Ms. Mahar said. "We couldn't understand why he wasn't feeling."

"Didn't it hurt?" she'd ask the growing boy. "No," Owen would say. "Well why not?" "I don't know, Ma."

Not until Owen was 3 -- the year he broke a bone in his foot and kept right on walking -- did the family from Bird Cove, Nfld., receive an explanation. Doctors told them their son had a rare and storied disorder -- a genetic condition that prevents the ability to perceive pain. He is normal in every other way, able to distinguish hot from cold and pat from pinprick; only the sensation of pain does not register.

The Newfoundland family is one of only 15 worldwide known to be affected by congenital indifference to pain, or CIP. But the curse of their inheritance could become a blessing for the rest of the world.

Scientists have found the mutant gene behind the bizarre condition and believe that mimicking its effects could lead to a new age of painkillers.

An international research effort led by Vancouver biotech firm Xenon Pharmaceuticals Inc. has confirmed that a single mutant gene is responsible for this rare pain disorder in nine families of different ethnicities in seven countries. Among them are the Mahars in Bird Cove, a 12-hour drive north from St. John's, where at least four members of three related families have been diagnosed, including Owen, now 20, and his brother Joshua, 11.

In a report to be published in the journal Clinical Genetics in April, the researchers list what patients have suffered without suffering -- double hip dislocations, lower-limb amputations, corneal abrasions, burns, stabs, gashes, head trauma and mutilating tongue-biting. A Swiss woman has experienced painless childbirth; one U.S. patient was able to undergo a cystoscopy, a painful exploratory bladder procedure, without anesthetic.

"It is somewhat surprising that one gene has such a profound effect," said study co-author Michael Hayden, co-founder of Xenon and a geneticist at the University of British Columbia. "This tells us that there is a primary target for pain perception that's most profound."

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