Variably protease sensitive prionopathy

**Definition:** A disease of the brain, caused by a mutation(s) in prion protein genes. This disease is characterised by deposition of abnormal prions in the brain leading to behavioural and mood changes, speech deficits, and progressive motor impairments. Confirmation is by pathological examination of the brain or identification of protease-sensitive prion proteins in a brain sample.

**Long definition:** Variably protease sensitive prionopathy (VPSPr) is a relatively newly described human prion disease, characterized by the accumulation of abnormal prion proteins which are variably protease sensitive. Notably, the abnormal prion protein is usually protease resistant. The clinical features of VPSPr are similar to that of cortical sCJD.