Single-Nucleotide Polymorphisms in SMARCA2 as Related to Frontal Lobe Gray Matter Volume in Individuals with Schizophrenia.

Schizophrenia is a debilitating mental disorder that affects approximately 1% of the world population and is associated with delusions, disorganized speech and behavior, hallucinations, and abnormal brain structure and function. The risk of developing schizophrenia is associated with both environmental and genetic risk factors. Schizophrenia is genetically heritable; it has been found that offspring have a 10% chance of inheriting the disease from an affected parent. Because of this genetic heritability, searches for schizophrenia genes have been long underway using genome-wide association studies (GWAS). One GWAS discovered gene is SMARCA2, a member of the SWI/SNF chromatin-remodeling complex. Single-nucleotide polymorphisms (SNPs) in SMARCA2 have also been associated with changes in gene expression. Koga, et al. associated SNPs in rs3763627 and rs3793490 with low SMARCA2 expression levels in the postmortem prefrontal cortex. Allelic determination of these two SNPs was performed for a selection of individuals with Schizophrenia and healthy controls using TaqMan genotyping assays. The data set was combined with magnetic resonance imaging (MRI) scans and calculated brain lobe volumes for each individual sample. It was found that the genotype GG in rs3793490 in affected individuals showed decreased frontal lobe gray matter volumes when compared to affected individuals who are T-carriers in the same SNP. However, this result cannot be concluded as statistically significant due to the small sample size of the GG group.