In current clinical practice, only family history is taken into account to detect cardiovascular diseases and cancers. However, generalizing the use of genetic tests would be more reliable. This is revealed by a study conducted in the United States.
Certain genetic changes, called “pathogenic variants”, considerably increase the risk of developing cardiovascular diseases as well as cancers. If screening to identify carriers is not included in current clinical practice, researchers mainly from the Massachusetts General Hospital focused on the benefits of genetic testing. Their findings were presented in a study published by the medical journal JAMA Network Open.
0.9% of participants carried a pathogenic variant
To carry out their work, the scientists analyzed data from 49,738 adults aged 40 to 69. Their family history was transmitted, as well as the sequencing of their exome, that is to say all the coding parts of their genome. Based on this latest information, the researchers focused on three genetic diseases in particular: familial hypercholesterolemia – which predisposes to cardiovascular disease – hereditary breast and ovarian cancer, as well as Lynch syndrome – which predisposes to cancer colorectal and uterine.
Result: 0.9% of participants were found to be carriers of a pathogenic variant. For 0.3% of them, they are affected by familial hypercholesterolemia, 0.5% by hereditary breast and ovarian cancer and 0.2% by Lynch syndrome. In addition, the risk of associated diseases is considerably higher for these individuals. It amounts to 21% for carriers in the first group (compared to 9% for non-carriers), 28% for those in the second (compared to 8% for non-carriers) and 22% for those in the third ( against 2% for non-carriers).
60% of carriers of a pathogenic variant had no family history
“What was really striking was that simply taking the family history — as I currently do in my clinical practice — would not have identified most high-risk individuals.”assures Amit V. Khera, lead author of the study and head of a research group at Massachusetts General Hospital, in a communicated published on the institution’s website.
Indeed, only 40% of people carrying a pathogenic variant reported the existence of a parent, brother or sister who had been affected by the associated disease. “Not to mention that the information was complementary: those who had both a family history and a pathogenic variant were the most at risk”says Amit V. Khera.
If identified, the risk can be reduced by various interventions
“Genetic testing is currently used primarily in people who are already sick, but these data really show the potential to screen much larger populations”, adds Dr. Aniruddh Patel. Because, if identified, the risk can be reduced by various interventions, such as drugs aimed at lowering cholesterol levels, early detection by mammography or colonoscopy, or even surgical interventions such as mastectomy and removal of the ovaries.
Now researchers are conducting genetic testing in a study of thousands of participants. Objective: to identify carriers of pathogenic variants in order to work with them and their health team to prevent the disease from developing.
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