ABSTRACT
Several recently published studies showed the existence of an association between the allele (4 of the apolipoprotein E and Alzheimer's disease (AD) in developed countries. We examined this association in 55 patients with possible or probable AD and 56 elderly controls referred to outpatient clinics at the "Hospital das ClÝnicas da Faculdade de Medicina da Universidade de SÒo Paulo "and "Centro de Saude Escola da Faculdade de Saude Publica da Universidade de Sao Paulo". The allele (4 was significantly more frequent among patients than controls (20.9 percent vs 8.9 percent, p=0.038). Thirty-six percent of the cases presented with at least one allele (4 compared with only 17.9 percent of the controls (p=0.027). The presence of at least one (4 allele increased by 2.63 times the risk of subjects being diagnosed as suffering from AD. All three (4(4 patients were male and had a pre-senile onset of the disease. There was no significant difference between senile and pre-senile cases (41.9 percent vs 29.2 percent, p=0.326) nor between men and women (36.0 percent vs 36.7 percent, p=0.959) regarding their risk of being (4. The age at onset of symptoms did not differ among the different genotype groups, although (4(4 cases showed a consistent trend for earlier onset. When only patients with the diagnosis of "probable AD" were included in the analysis (n=43), we observed that 22.1 perccent of the alleles were (4, a rate that was significantly higher than the 8.9 percent of controles (p=0.024). This study supports the association between the presence of the (4 allele and AD and extend this finding to Brazilian patients. Nonetheless, the presence of this allele is not necessary nor sufficient for the development of the disease and it is possible that its contribution to the pathogenesis of the disorder depends on the subject's ethnic group.