Fatal familial insomnia (FFI) is an inherited prion disease that shares characteristics of Creutzfeldt-Jakob disease (CJD); FFI and CJD are considered by some researchers to be extremes of a phenotypic spectrum. Experiments in Drosophila are described in the human disease model reports Creutzfeldt-Jakob disease, familial (FBhh0000791) and prion diseases (FBhh0000185).
Using mouse and hamster genes, variants associated with Creutzfeldt-Jakob disease (E200K in the human PRNP gene, see Mmus\PrnpCJD.3F4.UAS, Maur\PrpCJD.UAS) and fatal familial insomnia (D178N in the human PRNP gene, see Mmus\PrnpFFI.3F4.UAS, Maur\PrpFFI.UAS) have been characterized in flies.
[updated Feb. 2019 by FlyBase; FBrf0222196]
[FATAL FAMILIAL INSOMNIA; FFI](https://omim.org/entry/600072)
[PRION PROTEIN; PRNP](https://omim.org/entry/176640)
Fatal familial insomnia (FFI) is clinically characterized by insomnia with or without a diurnal dreaming state, hallucinations, delirium, and dysautonomia preceding motor and cognitive deterioration. [from MIM:600072; 2018.22.02]
There is considerable clinical and pathologic overlap between FFI and Creutzfeldt-Jacob disease (CJD); thus, FFI and CJD may be viewed as extremes of a phenotypic spectrum (summary by Zarranz et al., 2005; 16227536). [from MIM:600072; 2018.22.02]
Fatal familial insomnia (FFI) is associated with mutation in the prion protein gene (PRNP); it exhibits autosomal dominant inheritance. [from MIM:600072; 2018.22.02]
Variants implicated in FFI have also been found in patients diagnosed with Creutzfeldt-Jacob disease (CJD), supporting the view that FFI and CJD are extremes of a phenotypic spectrum (Zarranz et al., 2005; 16227536). [from MIM:600072; 2018.22.02].
The protein encoded by PRNP is a membrane glycoprotein that tends to aggregate into rod-like structures. Its primary physiological function is unclear; it may be required for neuronal myelin sheath maintenance. [Gene Cards, PRNP; 2018.04.19]
