prion disease pathway fatal familial insomnia pathway Fatal familial insomnia - an inherited prion disease, transmitted as an autosomal dominant trait, affecting primarily the ventral and dorsomedial nuclei of the thalamus and characterized by progressive insomnia, hallucinations, stupor, and coma ending in death within 6 months to 3 years of onset; autonomic and motor disturbances are also present. PW:0000267 pathway