HIGH APOLIPOPROTEIN-E EPSILON-4 ALLELE FREQUENCY IN AGE-RELATED MEMORY DECLINE

Many studies have demonstrated a strong association between the presen ce of one or two epsilon 4 alleles and Alzheimer's disease (AD), altho ugh few data are available on the apoiipoprotein E (APOE) epsilon 4 fr equencies at the preclinical stages of AD. Thus, with a view to determ ining whether APOE genotyping could be useful in the early detection o f AD, we determined the APOE allele frequencies in patients with memor y complaints without dementia (age-related memory decline, ARMD). We f ound an APOE epsilon 4 allele frequency of 0.315 in the ARMD group, si milar to 0.293 in the AD group, in contrast to 0.057 in the control gr oup. Significant differences (t = -2.91, df= 25, p = 0.008) were found between the Alzheimer's Disease Assessment Scale (ADAS) total scores in the ARMD patients with at least one epsilon 4 allele (mean = 24.2) compared with the ARMD patients without the epsilon 4 allele (mean = 1 4.7). Our results suggest that the patients with memory complaints, a high ADAS score, and the presence of-one or two APOE-4 alleles could b e at high risk for developing AD. Thus, we propose that genotyping in conjunction with the ADAS scale may prove useful as diagnostic markers of AD in the presymptomatic stages.