BACKGROUND: Fatal familial insomnia (FFI) is an autosomal dominant disease 
linked to a mutation in the prion protein gene. Fatal familial insomnia is 
characterized by sleep disturbance and loss of neurons, with gliosis in the 
thalamic nuclei.
OBJECTIVE: To describe the clinical, neurophysiological, radiological, and 
neuropathological data in a Chinese family with FFI.
SETTING: Tertiary referral university hospital setting.
PATIENTS: Patient 1 was a 36-year-old man who presented with insomnia and 
myoclonus. In the subsequent 9 months, he developed ataxia and dementia, 
followed by death. Patient 2 was the aunt of patient 1, and presented at the age 
of 47 years with insomnia, myoclonus, and dementia; her condition declined 
during a 12-month period. Genetic analysis was performed, followed by 
neuropathological and biochemical analysis of the disease-associated form of the 
prion protein PrPSc on the postmortem brain specimen.
RESULTS: Molecular analysis demonstrated an aspartic acid to asparagine mutation 
at codon 178 and homozygosity for methionine at codon 129. Both patients showed 
severe neuronal loss and prominent gliosis in the thalamus and brainstem 
involvement, with evidence of astrogliosis in the inferior olivary nucleus. 
Patient 1 also had neuronal loss and astrogliosis in the region of the superior 
colliculus and in the periaqueductal region. PrPSc was detected on Western blot 
analysis, and had a wide distribution. The strongest signals were present in the 
amygdala, hypothalamus, caudate, parahippocampal gyrus, periaqueductal gray 
matter, and mediodorsal thalamus.
CONCLUSIONS: To our knowledge, this is the first report of FFI in a family of 
Chinese descent. This supports the worldwide distribution of FFI, and despite 
differences in genetic background, the clinical and pathological findings are 
similar to those found in white patients with FFI.