I just looked it up, apparently there are two forms of Fatal Insomnia, one of them is inherited (autosomal dominant) and the other is caused by a prion (I didn't know that). There's a little more info available here: https://www.merckmanuals.com/professional/neurologic-disorders/prion-diseases/fatal-insomnia

However, it's known that, during sleep, the extent for gene expression in the brain rises and it's believed that the resulting proteins partially underlie the anatomical basis for memory and other developmental changes in the brain.