A nonsense mutation in the synaptogyrin 1 gene in a family with schizophrenia.

Chromosome 22q is one of the important regions repeatedly being implicated in schizophrenia. In this region, our group previously reported an association of a CAG repeat marker (22CH3) with schizophrenia in the Indian population. Because Synaptogyrin 1 (SYNGR1), associated with presynaptic vesicles in neuronal cells, lies within 1 million base pairs of this marker, it is a potential candidate gene for schizophrenia. We sequenced all six exons and flanking splice junctions of the SYNGR1 gene. We also carried out reverse transcriptase polymerase chain reaction and Northern blot analysis for exon 2 containing transcript of the SYNGR1 gene. We found a novel nonsense mutation (Trp27Ter) in exon 2 of the SYNGR1 gene in a family multiply affected with schizophrenia. Reverse transcriptase polymerase chain reaction and Northern blot analyses revealed that exon 2 containing transcript of this gene is expressed in the brain. Because the SYNGR1 gene is involved in presynaptic pathways, reduced levels of this protein might play some role in the pathogenesis of schizophrenia.