At the Institute of Human Genetics in Aachen, Germany, Dr Ingo Kurth is preparing for a rather unusual appointment. She’s collecting blood samples from Stefan Betz, a 21-year-old university student who suffers from a genetic disorder so rare that only a few hundred people worldwide are estimated to have it.

Betz has congenital insensitivity to pain, or CIP. It means he can place his hand in boiling water or undergo an operation without anaesthetic, and yet feel no discomfort whatsoever. In every other way, his sensory perceptions are normal. He sweats when a room is too hot, and shudders at the biting chill of a cold wind. But like almost all who suffer from CIP, Betz finds his condition a curse rather than a blessing.

People with CIP would love to know what pain means and what it feels like to be in pain

“People assume that feeling no pain is this incredible thing and it almost makes you superhuman,” Betz says. “For people with CIP it’s the exact opposite. We would love to know what pain means and what it feels like to be in pain. Without it, your life is full of challenges.”

As a young child, Betz’s parents initially believed he was mildly mentally retarded. “We couldn’t understand why he was so clumsy,” his father Dominic remembers. “He was constantly bumping into things and getting all these bruises and cuts.”

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