SIRPB1 copy-number polymorphism as candidate quantitative trait locus for impulsive-disinhibited personality.

Area of Science:

• Behavioral Genetics
• Molecular Psychiatry
• Human Genetics

Background:

• Impulsive-disinhibited personality (IDP) is a key trait linked to various behavioral disorders.
• IDP is known to have a significant heritable component, with genetics accounting for 30-60% of its variance.

Purpose of the Study:

• To identify novel genetic pathways associated with the IDP trait.
• To investigate the role of copy-number variants (CNVs) in IDP.
• To explore the functional impact of genetic variants on SIRPB1 gene expression.

Main Methods:

• Genome-wide analysis of CNVs in 261 male participants with extreme IDP scores.
• Quantitative trait locus analysis to identify candidate CNVs.
• Functional assays in zebrafish embryos to assess the effects of variants.

Main Results:

• A common CNV in the immune-related gene SIRPB1 was significantly associated with IDP scores in a dose-dependent manner.
• Higher SIRPB1 mRNA levels were observed with the deleted allele, suggesting altered gene expression.
• Functional assays confirmed that regulatory elements within the deleted region impact SIRPB1 expression.

Conclusions:

• SIRPB1 is proposed as a novel candidate gene contributing to phenotypic variations in IDP.
• The findings link SIRPB1 to disinhibitory behaviors and impulsivity control.
• Altered SIRPB1 expression may play a role in conditions like schizophrenia and other disorders involving disinhibition.