Both the association studies and expression studies didn't support a major role for SYN3 in the susceptibility of schizophrenia in Irish and Chinese populations.
The synapsin III (SYN III) gene on chromosome 22q is a candidate gene for schizophrenia susceptibility due to its chromosome location, neurological function, expression patterns and functional polymorphisms.
Variants in the genes coding for dopamine-D2 receptor, brain-derived neurotrophic factor (BDNF), neuropeptide Y (NPY), neuregulin 1, reelin and synapsin 3 showed association with schizophrenia, although few subjects were found in the minority allele for the two latter variants.