Based on the finding that the ratios of resPrPD-129 M and -129 V allotypes were highly variable, the authors concluded that, in MV2 and MV1 cases, normal or cellular PrP (PrPC)-129 M and -129 V had “similar tendency to misfold” into PrPD regardless of the MV histotype, and that “factors other than the PrPSc allotype abundance must influence the clinical progression and the phenotype of heterozygous cases of CJD”. Here, PRNP is linked to Creutzfeldt Jacob disease.