In addition, two fatal familial insomnia (FFI) cases in one family and 3 gCJD cases, G114V, T188K and E200K, were definitely diagnosed with the evidences of PrPSc in brain samples and/or special mutations in PRNP. Among them, two FFI cases and the G114V case had autopsy and were diagnosed as definite gCJD based on the neuropathological assays and Western blots. Here, PRNP is linked to fatal familial insomnia.