PRNP and variant Creutzfeldt-Jakob disease: Previously we have shown that cases of IPD caused by the PRNP point mutations P102L, D178N and E200K have a unique PrPSc glycoform ratio following proteinase K digestion, which differs significantly from PrPSc glycoform ratios observed in sporadic, iatrogenic and vCJD or IPD caused by octapeptide repeat insertional mutations (Hill et al., 2006; Wadsworth et al., 2006).