[Bit#13] Blessing or Curse? The People with the “Pain Switch” Turned Off

1. The Beginning of a Life Without Pain: What’s the Matter with a Child Who Feels No Pain?

2. The Culprit is the SCN9A Gene: Why Our Body’s Pain Pathway is Closed

When an impact occurs anywhere in our body, nerve cells send an electrical signal toward the brain, screaming, “Emergency!” However, for this signal to travel, it must pass through a specific “gateway.” Scientists call this the “sodium ion channel.” This gate must open for sodium to enter the cells, generating electricity that finally allows our brain to perceive pain.

The key master here is a gene called SCN9A. This gene acts as the blueprint for building that sodium channel gate. In patients with CIP, there is a fatal error in this blueprint, causing the gate to either never be built or to remain tightly shut. Even if a powerful impact breaks a bone, the electrical switch to the brain remains completely off. Why? Just one mistyped line in the genetic blueprint results in a state of perfect “insensitivity.”

Ultimately, the ability to feel pain is a “detection system” bestowed upon us by our genes. When this system stops, we continue living without even knowing that we are being destroyed. Isn’t it incredible that a single page of a blueprint can be the boundary between life and death?

3. The Disappearance of Survival Signals: The Lethal Threats Left in the Absence of Pain

Pain is the most powerful “defense system” protecting our bodies. A life where this system has collapsed is not one of freedom, but one akin to walking through a minefield every single moment. Most people rush to the hospital when appendicitis strikes because of the excruciating abdominal pain. However, CIP patients feel nothing until the appendix bursts and progresses into peritonitis. A bizarre situation unfolds where their internal organs are failing, yet they eat and sleep as if nothing is wrong.

A more serious issue is the damage to joints and bones. We stop walking and rest immediately even if we slightly sprain an ankle because of the pain. But those who don’t feel pain will keep walking and running until their ligaments are shredded. Eventually, their joints may be completely crushed, confining them to a wheelchair for life. Without the brake of pain, there is no way to prevent the body from exceeding its limits and self-destructing.

Even extreme heat is an unperceived threat to them. They might only pull their hand away from a frying pan once they smell their own skin burning. It is also common for them to suffer brain damage because they fail to detect high fevers exceeding 40°C (104°F). Pain is not just an unpleasant emotion; it is a vital prerequisite for survival that ensures we can wake up safely tomorrow. A life without pain is essentially a silent battle against an approaching death.

4. The Paradox of Modern Medicine: Could CIP Patients be the Key to Saving Humanity from Pain?

The tragedy of those who cannot feel pain is, paradoxically, becoming a powerful clue to saving hundreds of millions of chronic pain sufferers. Pharmaceutical companies worldwide are now focusing on their genes. Current potent painkillers, such as opioids, have fatal weaknesses like addiction and severe side effects. However, if we can mimic the SCN9A gene of CIP patients, the story changes. Instead of numbing the brain, we can create a “dream analgesic” that blocks the “pathway” where the pain signal originates.

The idea is clear: to temporarily replicate the phenomenon seen in CIP patients through medication. If we can selectively lock specific sodium channels, we could perfectly manage post-surgical or chronic nerve pain without the fear of addiction. In fact, a new class of painkillers based on this principle is undergoing clinical trials and is nearing commercialization. Ironically, the key to breaking the chains of suffering that have plagued humanity is held by the very people who cannot feel pain.

Ultimately, pain is both an essential device for survival and a challenge we must conquer. What is a mundane daily routine for one person is a desperate wish for another. Rather than envying a life without pain, why not try listening to and appreciating the small signals our bodies send us?