Ectopic expression of the novel locus Prnd, which is 16 kb downstream of Prnp and encodes a 179-residue PrP-like protein Doppel (PrPLP/Dpl), has been observed in the brain of Ngsk Prnp0/0 mice, but not in ZrchI Prnp0/0 brains, and has been implicated in the cerebellar degeneration of Ngsk Prnp0/0 mice [11], [16], [17]. The gene discussed is PRNP; the disease is cerebellar degeneration.