polygenic risk score
A quantitative measure of genetic liability to psychiatric disorders based on genome-wide association study findings.
Full Definition
A polygenic risk score (PRS) is a quantitative measure that aggregates the effects of many genetic variants across the genome to estimate an individual's genetic predisposition to developing a psychiatric disorder. These scores are derived from genome-wide association study results and weight each genetic variant by its effect size on disorder risk. In psychiatric epidemiology, polygenic risk scores are used to stratify populations by genetic risk, study gene-environment interactions, and investigate shared genetic liability across mental health conditions. While PRS can identify individuals at higher genetic risk, they currently have limited clinical utility due to modest predictive accuracy and population-specific training requirements.
Usage
Usage note: Emphasize limitations in clinical application when discussing predictive utility.
In Context
- "Individuals with high polygenic risk scores for schizophrenia showed earlier age of onset in the longitudinal study." — research publication
- "The polygenic risk score explained approximately 7% of the variance in depression liability." — genetic analysis