Genetic Creutzfeldt-Jakob disease affected monozygotic twins: Analysis of survival time, age at death and possible exogenous risk factors.

•First analysis of the age at death in monozygotic twins with gCJDE200K is presented.•Age at death in twins and siblings, all with genetic CJDE200K are compared.•The difference was not significant (may reflect the dominant genetic effect)•In twins the discordant age at death well correlated with exogenous risk.•Data support the role of analysed risks in accelerating the onset of gCJDE200K.