Rare Gene Mutation May Block Pain
Discovery Could Lead to New Pain Drugs, Scientists Say
Dec. 13, 2006 -- Scientists have discovered rare gene mutations that may block pain.
The mutations, found in the SCN9A gene, were spotted in six children in Pakistan who reportedly had never felt pain.
The discovery may lead to development of new pain drugs, write the researchers, who include C. Geoffrey Woods, MD, of England's University of Cambridge.
Their study is published in Dec. 14 issue of the journal Nature.
Since pain alerts people to the fact that they're hurt, having no sense of it can be dangerous.
For instance, if you couldn't feel pain, you might not yank your hand off a hot object, notes a journal editorial.
But pain can also be overwhelming, and scientists are always looking for new ways to safely tame the sensation.
The six children in Woods' study had reportedly been completely insensitive to physical pain since birth.
The kids came from three related families in northern Pakistan and ranged in age from 6 to 12. They had normal intelligence and showed no sign of nerve damage. Their other senses worked well; they could feel heat, cold, and touch.
One of the kids studied, a 10-year-old boy, regularly performed in "street theatre," the researchers write.
"He placed knives through his arms and walked on burning coals, but experienced no pain," Woods team notes. The boy died before turning 14 after jumping off the roof of a house.
The other children had frequent bruises and cuts. Most had broken bones at some point.
There were reports in the last century of other people who didn't feel pain, say Woods and colleagues, but they are "very rare," with "only a handful of such patients."
The researchers screened the DNA of the affected children -- except for the boy who had died after jumping off the roof, since his DNA wasn't available.
The DNA tests showed that the children had mutations in their SCN9A gene.
That gene makes a protein involved in sending pain messages (the sensation of pain) to nerves.
These gene mutations may have blocked the children from feeling pain, Woods' team notes.
If so, scientists may be able to make new pain relieving drugs that target the protein made by the SCN9A gene, the researchers write.
If the gene discovery bears fruit, "it might be possible to develop a new generation of drugs that can effectively mute the megaphone of pain," writes editorialist Stephen Waxman, MD, PhD, in Nature.
Waxman works in the neurology department at Yale University's medical school.