Lack of association between a single nucleotide polymorphism within the choline acetyltransferase gene and patients with Alzheimer's disease.

Alterations of the cholinergic system may account for typical clinical and pathophysiological disturbances of Alzheimer's disease (AD). In particular, a marked decline of choline acetyltransferase activity (CHAT) and as a consequence of acetylcholine during the course of the disease has been described. Due to the chromosomal localization of CHAT at 10q11.23 and its possible role in the pathophysiology of AD, CHAT may represent an appropriate candidate gene conferring risk to AD. In fact, a recent study identified a functional single nucleotide polymorphism (SNP) within the first common exon of CHAT, which was associated with AD giving an odds ratio of 3.8 (Neurosci. Lett. 333 (2002) 9). Because of the potential importance of this finding we analyzed this SNP and another functional SNP within exon 9 (rs868749) of the CHAT gene using a German case control sample consisting of 242 patients with AD and 143 cognitively healthy controls. No statistically significant differences were obtained for the previously described polymorphism. In addition, the exon 9 SNP (rs868749) was not polymorphic in the studied population. We conclude that the previously identified polymorphism is not associated with AD.