Implication of α1-antichymotrypsin polymorphism in familial Alzheimer's disease

A common polymorphism in the alpha 1-antichymotrypsin (ACT) gene has been shown to modify the Apolipoprotein E (ApoE) epsilon 4-associated Alzheimer's disease (AD) risk identifying the combination of the ACT/AA and ApoE epsilon 4/epsilon 4 genotypes as a potential susceptibility marker for AD. Using the polymerase chain reaction, we analyzed the segregation of the ACT and ApoE polymorphisms in familial Alzheimer's disease (FAD) patients carrying mutations in Presenilin (PS) and APP genes and in both early onset (EO) and late onset (LO) FAD patients without known mutations. Our data suggest that ACT does not represent an additional risk factor for PS and APP mutated families. However, in LOFAD patients a high frequency of the combined ACT/AA and ApoE epsilon 4/epsilon 4 genotypes suggest that ACT may interact with ApoE and play a role in LOFAD. (C) 1998 Elsevier Science Ireland Ltd.