Objective: Quantitative trait loci identified in animal models provide potential candidate susceptibility loci for human disorders. In this study, we investigated whether internalizing disorders (anxiety disorders, major depression, and neuroticism) were associated with a region on human chromosome 1 syntenic with a quantitative trait locus for rodent emotionality.
Methods: We genotyped 31 single-nucleotide polymorphisms in genes located on chromosome 1q31.2 in a two-stage association study of 1128 individuals chosen for a high or a low genetic risk for internalizing disorders from the Virginia Adult Twin Study of Psychiatric and Substance Use Disorders.
Results: None of the individual single-nucleotide polymorphisms showed consistent association across stages. A four-marker haplotype in the regulator of G-protein signaling 1 gene (RGS1) was significantly associated with decreased internalizing risk in both stages, whereas another showed a nominal association with a higher risk.
Conclusion: Our data suggest that markers in the RGS1 gene might be in linkage disequilibrium with a protective allele that reduces the risk of anxiety and depressive disorders.