SNAP-25 genotype influences NAA/Cho in left hippocampus.

The SNAP-25 gene is an integral part of the vesicle docking and fusion machinery that controls neurotransmitter release. Several post mortem studies revealed a reduction of SNAP-25 protein in the hippocampus of patients with schizophrenia and bipolar disorder (BD). Thirty-eight patients with schizophrenia, BD or obsessive-compulsive disorder and 17 healthy controls participated in the study. Proton magnetic resonance spectroscopy in left hippocampus was performed in each individual. Three single nucleotide polymorphisms (SNP) of the SNAP-25 gene were genotyped. Individuals with the homozygous CC genotype of the DdeI SNP presented a significantly higher ratio of N-acetyl-aspartate (NAA)/choline-containing compounds (Cho) in the left hippocampus compared to the group of individuals with the homozygous TT genotype. The SNAP-25 genotype may modulate synaptic plasticity and neurogenesis in the left hippocampus, and altered NAA/Cho ratio may be an indicator for this genetic modulation of neuronal function in the hippocampus.