OBJECTIVETo report and study a case of sporadic family fatal insomnia (SFFI) on its.

METHODSInvestigate clinical characteristics and family disease history of a suspect FFI patient. His clinical characteristic was analyzed, he and his 14 family members genomic DNA was extracted by standard techniques from their and blood detected with polymerase chain reaction (PCR) method and DNA sequencing to find out his prion protein (PrP) gene mutation. The patient's CSF was detected with Western-Blot method for 14-3-3 brain protein.

RESULTSThe patient was diagnosed as an sporadic FFI by his developed sleep disturbance and changes in sleep-awake rhythm, motor abnormalities, mental disorder, dementia, autonomic dysfunction; his family history; his 14-3-3 brain protein-positive (CSF) and analysis results of his PrP gene (codon point mutation D178N and methionine homozygosity at position 129M/M). Suggesting that in the future to identify CJD and FFI patients, screening should focus on clinical symptoms and laboratory results. The PrP gene of 14 family members did not appear Mutation, and there is no person suffering from the same disease.

CONCLUSIONSThe case was diagnosed as a sporadic familial fatal insomnia. Analysis of suspicious patients' genomic DNA for PrP gene mutation might be very important for FFI diagnosis because there exist many difficulties in clinical laboratory evaluation. This patient might be the first SFFI patient reported in China and the case finding might have momentousness in clinical and basical study.