Polymorphism C in the serotonin transporter gene in depression-free elderly patients with vascular dementia

Genotypes of the solute carrier family 6 (neurotransmitter transporter, serotonin) member 4 (SLC6A4) have been variously associated with depression, obsessive-compulsive disorder, memory impairment, and anxiety. Less clear are data regarding their association with severe dementia, in particular with vascular dementia (VaD).

To evaluate the possible involvement of different SLC6A4 genotypes/haplotypes in VaD.

The analysis of the 3 markers rs3813034, rs140701 and rs4795541 spanning the SLC6A4 locus was made in 541 consecutive patients clinically diagnosed as having VaD (n = 372) or no cognitive impairment (n = 169) attending a geriatric ward. A community-dwelling sample of 353 healthy subjects, as a reference for the genetic frequencies in the recruitment area, was also included in the study. All patients and subjects were free from any symptoms of depression, obsessive-compulsive disorder and anxiety. A complete neuroimaging documentation was available for all patients.

No important differences were observed in genotype distribution across the study groups. Similarly, no important differences were observed in haplotype distribution when a 3-point analysis was made.

Our findings suggest that polymorphism C in the promoter region of the SLC6A4 gene plays a minor role, if any, in the pathogenesis of VaD.