Is NRG1 involved in determining cerebral volumes in schizophrenia? Preliminary results showing a decrease in superior temporal gyrus volume

BACKGROUND/AIMS: Reduced left superior temporal gyrus (STG) volume is one of the most replicated imaging findings in schizophrenia. However, it remains unclear whether genes play any role in our understanding of such structural alteration. It has been proposed that Neuregulin 1 (NRG1) might be a promising gene involved in schizophrenia, because of its role in neurodevelopment and neuroplasticity. In this study, the association between NRG1 and STG anatomy in patients with schizophrenia was explored for the first time. METHODS: We investigated a 1-year treated prevalence cohort of patients with schizophrenia in contact with the South Verona Community-Based Mental Health Service. A blood sample was collected for DNA extraction and brain structure was assessed with an MRI scan. A total of 27 subjects with schizophrenia underwent both assessments and were included in the study. RESULTS: We investigated the association between the polymorphism SNP8NRG222662 (rs4623364) of NRG1 and volume of the STG. We found that patients homozygous for the C allele had reduced left STG gray and white matter volumes in comparison to those homozygous for the G allele (p < 0.01 and p < 0.001, respectively). CONCLUSIONS: This exploratory study suggests that NRG1 may be involved in determining STG size in schizophrenia, and may play a role in the neurogenetic basis of the language disturbances seen in this disorder. However, due to our small sample size, the results should be regarded as preliminary and replicated in a larger sample.