After learning about kuru in class, I wanted to know more about other kinds of prion diseases, including fatal insomnia. People with fatal insomnia die because, as the disease’s name suggests, they are unable to sleep. I wondered why this symptom is not characteristic of kuru. The answer is simple–kuru damages the cerebellum, while fatal insomnia damages the thalamus, which regulates sleep.
I was also interested to learn that fatal insomnia can be inherited, in which case it is called fatal familial insomnia. If one parent has a specific mutation in the gene for cellular prion proteins (PrPC), then their child has a 50/50 chance of inheriting that mutated gene and the disease it causes.
In other prion news, just today there was a discussion on NPR about the possibility that research on mad cow disease could lead to better treatment for Alzheimer’s and Parkinson’s. Researchers are considering ways to stop the chain reaction of improper protein folding caused by prions. A recent experiment has shown that neurons can be protected from the damaging effects of a certain kind of misfolded protein by replenishing the neurons’ supply of nicotinamide adenine dinucleotide (NAD). It’s possible that this discovery could help scientists develop treatments that could slow the progress of neurodegenerative diseases.
After reading your post I was interested in finding out more about inherited prion diseases. I learned that human prion diseases are grouped together according to whether they are sporadic, inherited, or acquired. Prion diseases are most often sporadic and least often inherited. While sporadic and inherited prion diseases occur in multiple populations worldwide, acquired prion diseases are more local- they affect specific populations and groups of people.