Genetics plays an important role in the development of disease, and genetic testing is often used to identify rare, heritable diseases where the presence of a single genetic variant is highly predictive of disease. However, common diseases – which account for most of the healthcare burden – are not caused by single, high impact genetic variants. Rather, the genetic element of risk usually arises from the effect of multiple genetic variants. These are much harder to identify and assess, making risk prediction harder.
One recent development is the polygenic score, a means of aggregating information from these multiple small-effect genetic variants to assess risk for a given disease. Polygenic scores combine information from multiple genetic variants into a single score that can be used to examine risk. Recent advances in this field have reignited interest in using genetic information in personalised prevention approaches for common conditions such as cancer and heart disease.
