Association between a genetic variant of the alpha-7 nicotinic acetylcholine receptor subunit and four types of dementia.

We tested the hypothesis whether the partially duplicated variant of alpha7 nicotinic acetylcholine receptor subunit gene (CHRFAM7A) 2-bp deletion (-2 bp) polymorphism and apolipoprotein E (ApoE) epsilon4 allele confer susceptibility to Alzheimer's disease (AD), dementia with Lewy bodies (DLB), Pick's disease (PiD) and vascular dementia (VD). The study included 175 AD, 35 DLB patients, 38 PiD, 96 VD and 175 healthy control (HC) probands. The CHRFAM7A genotype without the -2 bp allele was significantly over-represented in AD (p = 0.011), DLB (p = 0.001) and PiD (p < 0.0001) compared to HC, but there were no statistical differences in VD (p = 0.407) compared to HC. We confirmed again that the ApoE epsilon4 allele is a risk factor for dementias. The -2 bp polymorphism of CHRFAM7A can be implicated in AD, DLB and PiD. However, it is unlikely that it plays an important role in the pathogenesis of VD.