Promoter polymorphism of the 5-HT transporter and Alzheimer's disease

The role of the deletion/insertion polymorphism within the promoter region of the serotonin transporter gene (5-HTT) is under discussion as a potentia l genetic risk factor for Alzheimers's disease (AD). Here we report signifi cant differences in the allelic distribution of this polymorphism with a hi gher frequency of the short variant allele in AD patients when compared to controls. This difference was independent of the apolipoproteinE genotype. Thus, our study supports the notion that genetic alterations in the seronto nergic neurotransmitter system may be involved in the etiopathogenesis of A D. However, given the reported negative findings, we are presently trying t o identify diagnostic subgroups for which the 5-HTT promoter polymorphism r epresents a susceptibility locus. (C) 2000 Elsevier Science Ireland Ltd. Al l rights reserved.