<prompt> Fatal familial insomnia is associated with:Prion diseaseDegenerative diseasesNeoplastic diseasesVascular diseases  <response>: Ans. is a i.e., Prion diseaseFatal familial insomnia: Patients with this illness present with intractable insomnia, dysautonomia, dementia and motor paralysis. Death occurs within 6 months to 3 years following presentation. The clinical presentation of the disease, however, varies widely; hence definitive diagnosis of the condition is made by genotyping. 