Preliminary evidence for anticipation in genetic E200K Creutzfeldt-Jakob disease

Creutzfeldt-Jakob disease (CJD) linked to the E200K mutation of the prion p rotein (PrP) gene presents within a wide range of phenotypic heterogeneity, including the age at disease onset. We report an earlier disease onset for mutation carriers of the offspring generation when compared with that of t heir parents, suggesting the possibility of anticipation. A still unidentif ied environmental or genetic element may affect the age at onset in mutatio n carriers of different generations.