FIRST EXPERIMENTAL TRANSMISSION OF FATAL FAMILIAL INSOMNIA

ORIGINALLY described by Lugaresi et al, in 1986 (ref. 1), fatal famili al insomnia (FFI) is a rare inherited neurological disease characteriz ed by the subacute progression of intractable insomnia and other auton omic abnormalities, cerebellar and pyramidal signs; myoclonus and deme ntia; neuropathologically, the major feature is severe neuronal loss w ith associated gliosis in the ventral and mediodorsal thalamic nuclei. The disease has been related to the group of spongiform encephalopath ies by virtue of the presence of low levels of proteinase-resistant am yloid protein (PrPres) in the brain(2-4), and of a pathogenic single-a llele mutation at codon 178 of the PRNP gene that encodes PrPres (refs 2, 5). Here rye report the successful transmission of the disease to experimental animals, placing FFI within the group of infectious cereb ral amyloidoses.