Age of disease onset in people with familial Creutzfeldt-Jakob disease was approximately 9 years earlier relative to their diseased parents. However, missing data may misrepresent a true genetic anticipation in familial Creutzfeldt-Jakob disease.
Why this matters
There are conflicting reports over the existence of anticipation in familial Creutzfeldt-Jakob disease—a phenomenon whereby the symptoms become apparent at an earlier age in sequential generations. Understanding methodological difficulties in longitudinal studies may help to validate reports of anticipation in other genetic diseases.