OBJECTIVE: Fatal familial insomnia (FFI) is an autosomal dominant prion disease 
characterized clinically by inattention, sleep loss, dysautonomia, and motor 
signs. This study is aimed to investigate clinical and familial characteristics 
of ten Chinese Patients with FFI.
METHODS: We identified ten FFI cases from the surveillance network for 
Creutafeldt-Jakob disease (CJD) in China. Final diagnosis of FFI cases was made 
in accordance with the WHO criteria for CJD. The main clinical features and 
family histories of these ten FFI cases were analyzed.
RESULTS: The median age of ten cases at onset was 38 years (from 19 to 55). The 
foremost symptoms seemed to be various, including sleep disturbances, vision 
disorder, dizziness and anorexia. Sleep disturbances appeared in all cases and 
lasted in the whole clinical courses. Progressive sympathetic symptoms, memory 
loss, movement disturbances, myoclonus and hypertension were also frequently 
observed. The median duration of the disease was 9.5 months. EEG and MRI did not 
figure out special abnormality. 14-3-3 protein in CSF was positive in five out 
of eight tested patients. Clear family histories were identified in 8 patients.
CONCLUSION: The data from our study confirm that the Chinese FFI cases have 
similar clinical characteristics as that of the Caucasian cases. Compared with 
other genetic CJD associated mutations, the genetic frequencies of D178N in PRNP 
are apparently high among the Chinese cases.