Association between ACE polymorphism, cognitive phenotype and APOE E4 allele in a Tunisian population with Alzheimer disease.

Angiotensin-converting enzyme (ACE) has shown altered activity in patients with neurological diseases. An insertion/deletion (I/D) polymorphism of the ACE gene encoding angiotensin-converting enzyme has been reported to be associated with the risk for Alzheimer's disease (AD), and is generally considered to be a disorder primarily affecting memory. We conducted a case-control study in a sample composed of 85 sporadic AD patients and 90 age- and sex-matched controls to investigate the possible effect of the polymorphism and cognitive profile. Our data revealed an association between the ACE polymorphism and AD risk. There was a significant difference in the ACE allele or genotype frequencies between cases and controls. The D/D genotype showed an increased risk for AD and in the amnestic group and the effect was independent on ApoE genotypes.