Polymorphism of the 5'-upstream region of the human SNAP-25 gene: an association analysis with schizophrenia.

Recent studies have suggested that synaptic abnormalities may be part of the pathophysiology of schizophrenia. SNAP-25 (synaptosomal-associated protein of 25 kD) is one of the synaptic proteins responsible for presynaptic neurotransmission, axonal elongation and synaptogenesis. Genetic variation in the 5'-upstream region of the SNAP-25 gene was analyzed in 87 unrelated schizophrenic patients and 100 healthy controls. A novel polymorphic (TAAA)(n) tandem repeat was identified in the 5'-upstream region. There were no significant differences between the patient and the control groups in the distribution of repeat numbers of alleles or genotypes. In addition, no associations were found between the polymorphism for subtypes, longitudinal courses or positive family history of the patients. Our results suggest that polymorphisms in the 5'-upstream region of the SNAP-25 gene have no association with schizophrenia.