GENOMIC TESTING REVEALS HEREDITARY RISK
IN NEARLY 12% OF HEALTHY PEOPLE, STUDY FINDS
CHICAGO – Nov. 19, 2020 – More than one in 10 people who had predictive genomic testing – which looks for genetic mutations in otherwise healthy people – learned that they had a hereditary risk for a health condition and might benefit from preventive care, according to a study being presented at the National Society of Genetic Counselors (NSGC) 39th Virtual Annual Conference.
The first to assess predictive genetic testing in a clinical, or real-world setting, the study found nearly 12% of people had findings that were “clinically actionable,” meaning they had gene variants, known as mutations, that increased their risk for various types of cancer, cardiovascular disease or a negative reaction to anesthesia and therefore might be candidates for preventive care, such as regular screening, preventative surgery or receiving or avoiding specific anesthetics.
“About half of patients with a hereditary risk for cancer or a cardiovascular disease did not have a personal or family medical history that would suggest they had this risk, meaning it likely would not otherwise have been identified,” said Jennifer L. Anderson, MS, CGC, lead author of the study and a genetic counselor at Mayo Clinic Center for Individualized Medicine in Rochester, Minn. “Our findings suggest that many people who are generally healthy may have a genetic risk and broader adoption of predictive genomic testing could be beneficial in routine medical practice, ideally including genetic counseling.”
Between 2014 and 2019, 301 of 1,281 patients seen at Mayo's Predictive Genomics Clinic – where diagnosis and treatment are tailored to each person – decided to pursue predictive genetic testing. Overall, 35 of the 301 patients (11.6%) had a gene variant that was associated with a hereditary risk, most commonly in the BCHE, BRCA2, CHEK2, LDLR, MUTYH or MYH7 genes, which are associated with various health issues such as a potential negative reaction to certain types of anesthesia, breast and ovarian cancer, colon cancer, high cholesterol or heart conditions. Of the 29 patients with hereditary cancer or cardiovascular risks identified, 15 (51.7%), had no family or medical history of the genetic risk.
Additionally, 168 (55.8%) were carriers of at least one recessive gene, meaning while their health likely isn’t affected, their children’s health could be. If both parents carry the same recessive gene and pass it on, the child would have a risk for the genetic condition. Further, 128 (42.5%) had a gene mutation that was associated with multifactorial disease, in which a gene is just one of a number of aspects – including lifestyle choices and the environment -- that contribute to the risk for developing a health condition, such as late-onset Alzheimer’s disease.
The rate of people who decided to pursue testing at the clinic increased from 11% in 2014 to nearly 40% in 2019. “We have found that patients are increasingly interested in this type of predictive test and want to learn about their genetic risk for diseases, even if they do not have a personal or family history of those conditions,” said Anderson. “Genetic counseling is an important part of predictive testing by helping patients understand the results and their options for preventive care.”