The effects of APOE genotype on age at onset and progression of neurodegenerative diseases.

APOE genotype influences the age at onset of some neurodegenerative diseases such as AD and the rate of progression in others such as MS. The authors hypothesize that APOE genotype ubiquitously determines the efficacy of neuronal maintenance and repair in these diseases and that the seemingly divergent clinical effects are due to the stage of disease at which the diagnosis is made. Early diagnosis facilitates the measurement of effects on disease progression rate, whereas late diagnosis results in a marked effect of APOE genotype on disease onset.