Gerstmann–Straussler–Scheinker syndrome (GSS) is a very rare type of prion disease most commonly inherited via an autosomal dominant pattern with mutations in the PRNP gene at codons 102 (most common), 105, 117, and 198, located on chromosome 20. Though the clinical manifestations of GSS depend on the mutation inherited, most of these patients will develop symptoms of ataxia, spasticity, and rigidity in the early phases of the disease, as well as dementia in the later stages. Those with GSS typically develop symptoms in their 40s to 70s, which progress rapidly, with death typically 5–10 years after onset.