PRNP and sporadic Creutzfeldt-Jakob disease: In this context, although the clinical presentation of most sporadic CJD patients is distinct from kuru, atypical forms of sporadic CJD are well recognized (Gomori et al. 1973; Brown et al. 1984; Parchi et al.1996, 1999; Hill et al. 2003; Collins et al. 2006), and notably a relatively rare sub-type of sporadic CJD associated with long clinical duration and progressive ataxia also shows prominent kuru-type PrP plaques (Parchi et al.1996, 1999; Hill et al. 2003).