Association of the schizophrenia susceptible gene DKK4 with brain volume in Chinese populations

Schizophrenia is one of the most severe mental disorders with a worldwide incidence of 1%. Previous studies suggested that the brain volumes of the schizophrenia patients were much smaller than the healthy individuals and many schizophrenia susceptible genetic variants have been shown associated with structural brain abnormalities in patients, which is consistent with the neurodevelopmental hypothesis of the etiology of schizophrenia. Recently, the DKK4 gene involved in the Wnt signaling was found to be significantly associated with schizophrenia. To test whether DKK4 is associated with neurodevelopment, we genotyped one DKK4 SNP in 961 healthy Chinese individuals and measured their brain volumes. We found that the SNP was significantly associated with brain volume under both additive and dominant genetic models, providing evidence that schizophrenia susceptible genes could influence brain volume. Our findings support the neurodevelopmental hypothesis of the etiology of schizophrenia.