Researchers discover gene linked to pain sensitivity

This genetic discovery could pave the way to more effective treatments to tackle pain without the debilitating side effects of current drugs.

Lead researcher Dr. Geoffrey Woods, a medical geneticist from Cambridge University, said, "The search for effective analgesics with acceptable side effects has long been the goal of doctors and biomedical researchers.

"Because current therapies have limited efficacy, with up to 50 per cent of treated subjects receiving inadequate pain relief, there exists a significant need to develop better therapies.”

Genetic variations explored
In an effort to understand why some people lack the ability to feel pain while others are more vulnerable, the researchers examined the DNA of 578 people with osteoarthritis.

They came across a gene which also existed in patients with sciatica, phantom pain, back problems, and pancreatitis.

Then they thoroughly analyzed the limits of pain of 186 healthy women and found that those with a higher perception of pain and less tolerance of it had the same gene.

The researchers identified the culprit as the SCN9A gene, which plays a key role in controlling sodium channels inside nerve cells.

According to scientists, malfunction in the gene causes the sodium channels to open too easily or not close at all which triggers electrical signals to the brain, producing sensations of dull excruciating pain.

Implications of the study
Doctors are optimistic the breakthrough would help develop effective painkillers designed to modify the protein's activity.

Additionally, the study could give some insight into the genetic reasoning behind the variation of responses of patients to different painkillers.

Explaining the mechanism, Dr Woods said, "As a sense, pain serves as an adaptive mechanism that protects us from tissue damage by alerting us to events that are capable of producing injury and evokes behaviors that promote tissue healing.

"However, the development of maladaptive persistent pain states in response to tissue injury is common, with one in six adults suffering from a chronic pain condition.”

He further added, "As individuals appear to have differing genetic susceptibilities to pain, future studies should be directed toward understanding whether responsiveness to different classes of analgesics is also genetically determined.”

The findings have been published in Proceedings of the National Academy of Sciences.