Gerstmann-Sträussler-Scheinker syndrome (GSS) with the P102L mutation is a rare genetic prion disease caused by a pathogenic mutation at codon 102 in the prion protein gene. Cluster analysis encompassing data from seven Czech patients and 87 published cases suggests the existence of four clinical phenotypes ("typical GSS," "GSS with areflexia and paresthesia," "pure dementia GSS," and "Creutzfeldt-Jakob disease-like GSS"); GSS may be more common than previously estimated.
In making a clinical diagnosis or progression estimates of GSS, MRI, and RT-QuIC may be helpful, but the results should be evaluated with respect to the overall clinical context.