A woman who has never been able to feel pain got her first taste of it recently, and she told doctors that she "quite enjoyed it."

The woman, who prefers to remain anonymous, has a rare genetic mutation called Nav1.7. This condition blocks the pathway of sodium ions used to conduct pain among the nerves. Babies born with this genetic mutation have to be watched carefully because they will chew on their fingers, toes, and even lips until they bleed — unaware that they are causing themselves harm. As they get older, they are more at risk than other toddlers from burns, falls or other accidents.

Over the years, researchers have developed drugs that simulate the conditions of this mutation in the hopes of helping sufferers of chronic pain, but efforts so far have been disappointingly ineffective. Now, thanks to this Jane Doe, researchers are able to better understand the condition and how it creates the insensitivity to pain.

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The research, led by John Wood of University College London, looked at how the genetic mutation blocks pain. He has shown in previous animal and human studies that this mutation causes higher-than-normal levels of opioids in the brain. Opioids are the body’s natural painkillers.

Woods used naxalone, the same opioid blocker used to treat heroin addiction. He found that after administering the drug, both the mice and the woman were able to feel pain again. It was mild pain — just a low heat from a laser — but the woman could feel it and she told researchers that she quite enjoyed the experience. (That makes sense when you consider that she's 39 and has never felt pain before; it was a novel experience.)

Woods and his team hope that this research, which has given them a better understanding of the Nav1.7 genetic mutation, can finally help them develop better treatment methods for sufferers of chronic pain.

The study was published in the journal Nature Communications.