Congenital Insensitivity to Pain: The Mutation of the SCN9A Gene

Pain Free, Better Life? Not so much.

In a more recent module, some articles discussing individuals who do not feel any physical pain were read and reviewed on the piazza site. At first you think, "How awesome would that be, feeling absolutely no pain? I could do anything I want and not be affected by it at all!" However, according to scientists and doctors, the ability to feel pain is one of the most important signals our bodies give us when something isn't right. Pain signals our body when we are pushing it too far, it sets limits for us.

Ashlyn Blocker, a young girl from Georgia, suffers from a disorder called congenital insensitivity to pain. She can feel pressure, textures, and temperatures, but doesn't feel the pain that can be associated with these things. Ashlyn was diagnosed at a younger age when she was taken to the doctor because of a swollen eye. At first the doctors thought she just a had more severe case of pink eye, but when she didn't respond well to treatment, they sent her to an ophthalmologist who diagnosed her with a corneal abrasion, something that should be quite painful. After going to yet again another specialist, and going through numerous tests Ashlyn was diagnosed. Similarly, doctors in Northern Pakistan researched a family of six children who also suffered from the same diagnosis. They felt no pain, suffering from various cuts, bruises, broken bones, and more, these children were the amusement of others who were amazed by their lack of physical feeling. 

Ashlyn  Blocker

Both Ashlyn and the family of children who were studied all had a similar mutation. This mutation was found on the gene SCN9A. Nerves that sense pain are all along the body's surface and normally fire frequently when we touch something that is painful, like something hot or sharp. This sends electrical signals to our brains which then causes our bodies to react. These electrical signals are generated by molecular channels produced by the SCN9A gene. The mutation on the gene prevents it from making the channel, which then causes the electrical impulses to never be produced. 

According to Dr. C. Geoffrey Woods, a physician at Cambridge University who researched and worked with the Pakistani families, found that "the SCN9A gene is active in both nerves that mediate pain and in those of the sympathetic nervous system." However, none of these families suffered from any sympathetic nervous system disorders. This lack of side effects to the sympathetic nervous system is crucial to drug developers and researchers, and may help them target some kind of pain reliever. Dr. Woods also discusses how not all pain reception is controlled by one gene, and how it is surprising that a single gene mutation is responsible for a complete lack of feeling of physical pain. However, he found that the proteins made by the SCN9A gene cause the initial activity of the signal that is sent to the brain, and believes that because all pain fibers depend on this gene, when it is mutated, all those other fibers are altered as well.

Overall, this disorder is extremely rare and needs to be taken very seriously. A lot of cases of congenital insensitivity to pain end in premature death, with many serious injuries along the way. As I researched the topic more, I realized how thankful I am to be able to feel pain and know when my body needs a break or is getting pushed past its limits. Pain, in a way, is a gift that often goes unappreciated for all the things it does for us. Pain, although it hurts, is one of our body's best friends. 

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