Fatal familial insomnia
Abbreviated FFI.
An hereditary prion disease characterized by disrupted sleep (insomnia), motor abnormalities (myoclonus, ataxia, dysarthria, dysphagia, and pyramidal signs), and hyperactivation of the autonomic nervous system.
Due to a missense mutation at codon 178 of the prion protein gene on chromosome 20. A sporadic form of fatal insomnia is also known