Apolipoprotein E and intronic polymorphism of presenilin 1 and alpha-1-antichymotrypsin in Alzheimer's disease and vascular dementia

Apolipoprotein E (ApoE) genotypes, presenilin 1 (PS-1) and alpha(1)-antichymotrypsin (ACT) polymorphism and the association of the genotypes were examined in patients with Alzheimer's disease (AD, n = 121) or vascular dementia (VD, n = 68) in comparison with elderly controls (n = 125). The frequency of the ApoE epsilon 4 allele was significantly increased both in late-onset AD (0.35) and in VD (0.17); the frequency of ApoE epsilon 2 was significantly reduced in AD, but it was similar in VD and controls. The presence of the allele 1 of PS-1 intronic polymorphism was not associated with AD or VD and was not influenced by the ApoE genotypes. Also, the frequency of allele A of the intronic polymorphism of ACT was similar in AD, VD and controls and it was not altered by ApoE or PS-1 genotypes. The results confirm the association between ApoE epsilon 4 and AD and indicate an increase in ApoE epsilon 4 in Vd, too. A potential protective role of ApoE epsilon 2 is also suggested for late-onset AD but not for VD. No association was shown between ACT allele A and PS-1 allele 1 in AD or VD.