Does the prion protein gene 129 codon polymorphism influence sleep? Evidence from a fatal familial insomnia kindred

OBJECTIVE: Experimental and clinical evidence in prion diseases suggests that the prion protein gene (PRNP) plays a role in regulating sleep. METHODS: Seventeen healthy individuals belonging to a single fatal familial insomnia pedigree, 8 carriers and 9 non-carriers of the PRNP codon 178 mutation, underwent polysomnography and spectral electroencephalographic (EEG) analysis. All were also characterized with regard to the codon 129 polymorphism on both PRNP alleles. RESULTS: PRNP codon 129 polymorphism exhibited influences on sleep-EEG activities. In particular, spindle frequency band power and balance between delta and spindle activity were found to correlate with the genotype of PRNP codon 129, irrespective of the mutation at codon 178. CONCLUSIONS: Our data suggest that PRNP codon 129 polymorphism may also affect sleep in the healthy population and warrant further studies in the general population and other sleep disorders.