A new study from the University of Helsinki demonstrates the added value of genetic information in measuring the risk of inherited diseases alongside the widely used family history assessment.
Family history is widely used by doctors to assess an individual’s risk of developing common diseases such as coronary heart disease, diabetes and cancer. In recent years, polygenic risk scores based on genome-wide DNA testing have been developed to measure genetic susceptibility. The polygenic risk score comprehensively measures an individual’s own genetic risk factors.
A study by scientists from the University of Helsinki has now compared these two measures for more than twenty common diseases. The study looked at diseases such as cardiovascular disease, common cancers and musculoskeletal disorders. The results show that both family history and polygenic risk score measurements provide complementary information for assessing susceptibility to inherited disease.
Clinicians have wondered what polygenic risk assessment adds to the seemingly simple question of family history. Our new results show that these two measures complement each other. In addition, their combination provides the most accurate information for assessing the risk of hereditary diseases.”
Nina Mars, first author of the study, Institute for Molecular Medicine Finland (FIMM), University of Helsinki
The study is based on data from the FinnGen research project with more than 300,000 participants in the Finnish biobank.
The data showed that the risk of the disease was particularly high if the individual had affected family members and a higher than average polygenic risk.
The results also show that the lower-than-average polygenic risk offset the risk-enhancing effect of family history. This means that the risk of individuals with a low polygenic risk score was not increased even if they had a family history of the disease. Findings were similar across diseases.
Genetic information is more personalized than family history
Although polygenic risk describes an individual’s own genetic susceptibility more accurately than family history, it does not replace family history. According to the research team, there are several reasons for this.
“For example, a family history can provide information about non-genetic factors shared in a family, such as lifestyle. However, a family history does not provide individualized information. For example, a mother’s illness would lead to a similar family history in all siblings.” even though each sibling inherited a unique combination of genetic factors from both biological parents. Polygenic risk assessment measures this unique set of genetic risk factors,” says Nina Mars.
Polygenic risk measurement is currently not widely used in clinical care to assess disease risk.
“Our results add to previous studies that have demonstrated the added value of polygenic risk assessment to existing clinical risk prediction tools. Additionally, polygenic risk information can be assessed simultaneously in a large number of diseases, including those where family history is difficult to ascertain.” And who among us even knows or remembers all the illnesses of our relatives?” asks Professor Samuli Ripatti from the University of Helsinki, who led the study.
Link to journal:
Mars, N., et al. (2022) A systematic comparison of family history and polygenic risk across 24 common diseases. American Journal of Human Genetics. doi.org/10.1016/j.ajhg.2022.10.009.
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