A pain-sensing gene has been discovered by researchers, potentially paving the way for a new generation of treatments to reduce or eliminate physical discomfort.
Congenital insensitivity to pain (CIP) is a disorder found in one in a million people, one which prevents them from ever feeling any pain. Although this seems like it would be a blessing, the condition can result in injuries or diseases going untreated for long periods of time.
"The affected children usually come to our attention when their baby teeth start to erupt because they start to bite their own tongue, lips and fingers and, in some cases, even bite bits of them off. They are also susceptible to bone fractures, which can go unnoticed for a long time because they cannot feel pain," Michaela Auer-Grumbach from the Medical University of Vienna said.
Researchers examined 11 families in Asia and Europe who have members with the condition.
The PRDM12 gene was found to be mutated in those people unable to experience pain. This is just the fifth gene identified to play a role in the sensation. Pain-sensing neurons were also found to be absent from nerve biopsies taken from patients with CIP.
"The ability to sense pain is essential to our self-preservation, yet we understand far more about excessive pain than we do about lack of pain perception. Both are equally important to the development of new pain treatments — if we know the mechanisms that underlie pain sensation, we can then potentially control and reduce unnecessary pain," said Geoff Woods of the University of Cambridge.
The PRDM12 gene was already believed to play a part in modifying chromatin, which acts like a switch, turning genes on and off. Chromatin is active during the production of certain types of cells, including nerves, which could explain how the complex can turn off the manufacture of nerves that transmit pain signals.
Discovery of the genetic markers underlying CIP could help researchers devise new methods of testing children who may have the disorder, allowing health care professionals to provide those patients and their families with appropriate counseling and guidance. This data could also lead to the development of a new generation of treatments for pain in patients without CIP.
Pain is not pleasant, but the sensations evolved as a way to warn living beings of injuries and dangers in the environment. People affected by CIP often live shorter than normal lifespans due to accumulated injuries.
Analysis of the role of PRDM12 in congenital insensitivity to pain was profiled in the journal Nature Genetics.
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