APOLIPOPROTEIN E4 ALLELE IN A POPULATION-BASED STUDY OF EARLY-ONSET ALZHEIMERS-DISEASE

Several studies have reported an association of the apolipoprotein E a llele epsilon 4 (APOE4) to familial and sporadic late-onset Alzheimer 's disease (LOAD). Here we report on the relationship between APOE4 a nd early-onset Alzheimer's disease (EOAD) in a Dutch population-based study. The frequency of the APOE4 allele was 2.3 times higher among E OAD cases compared to controls. Among patients, the allele frequency w as 1.6 times higher in those with a positive family history than in th ose without. A significant increase in risk of EOAD was found for subj ects homozygous for APOE4 regardless of family history of dementia, b ut an increase in EOAD risk for APOE4 heterozygotes could only be sho wn in subjects with a positive family history. Our study demonstrates a significant association between APOE4 and EOAD which is modified by family history of dementia.