Struggling to sleep can be incredibly frustrating, but for those with a rare condition called fatal familial insomnia (FFI), sleeplessness can become a life-threatening issue. FFI is a brain disorder that eventually robs individuals of their ability to sleep entirely, leading to death.

What Is Fatal Familial Insomnia?

FFI is an exceptionally rare genetic condition that affects the brain and nervous system. It impacts only about one to two people per million, making it difficult to diagnose and even harder to spot early.

Cause of FFI

FFI is caused by a mutation in the prion-related protein gene (PRNP), which produces a protein called PrPC. This protein plays a critical role in regulating body functions, including sleep.

To explain the mutation, the Cleveland Clinic uses a relatable analogy involving folding laundry:

“When there’s a mutation on the PRNP gene, the amino acids that build the PrPC proteins don’t have instructions to build the proteins correctly. This mutation is similar to folding your laundry,” the clinic explains.

“If you’re unsure how to fold a t-shirt, you might ball up the fabric and put it in a drawer. Over time, that drawer progressively becomes difficult to close because you collect several t-shirts that aren’t folded correctly.

“Misfolded t-shirts are like PrPC proteins that collect in your brain and become toxic to the cells in your nervous system, causing symptoms.”

FFI can be inherited, and only one parent needs to pass on the faulty gene for their child to inherit the condition. In rare cases, it can also occur spontaneously, even without a family history.