Mutations of the prion protein (PrP) gene are present in patients with Gerstmann-Sträussler-Scheinker syndrome (GSS), familial Creutzfeldt-Jakob disease (CJD), and fatal familial insomnia (FFI). We developed a denaturing gradient gel electrophoresis (DGGE) strategy that readily identifies point mutations in the PrP coding sequence. By comparison with appropriate controls, haplotypes often may be deduced. This method permits samples from many patients with GSS, CJD, as well as patients with unusual degenerative neurologic disorders, to be screened rapidly, sensitively, and inexpensively for the presence of known and novel PrP mutations. We illustrate the sensitivity of this approach by reporting 2 novel polymorphisms in the PrP coding sequence.