Don’t expect any yes/no outcomes from genetic testing for inherited cardiovascular disease, Australian cardiologists have been reminded.
In an editorial in Heart, Lung and Circulation, Dr Belinda Gray and Professor Chris Semsarian said genetic testing results were not binary, “but rather, fall along a probabilistic spectrum of pathogenicity”.
In addition, there was the possibility of variants being reclassified between the current categories of benign, likely benign, variant of unknown significance, likely pathogenic and pathogenic.
“Given the possibility of variants being reclassified, it is important that there is periodic recontact with patients and families after genetic testing is performed in some instances,” they wrote.
“Therefore, in the Australian health care setting, we would advise that genetic testing is best performed as part of a specialised multidisciplinary cardiac genetics clinic.”
The editorial provides a short summary of the recent AHA Scientific Statement on genetic testing for cardiovascular disease.
Conditions with a largely monogenic cause included cardiomyopathies, arhythmic disorders, heritable thoracic aortic aneurysms and dissections, and familial hypercholesterolemia.
Dr Gray and Professor Semsarian, from the Royal Prince Alfred Hospital and University of Sydney, said there was a temptation to test for more and more genes however that approach was most likely to return more variants of uncertain significance.
“Therefore, targeted genetic testing is recommended for genes known to be associated with the phenotype in question.”
The editorial included a list of key genes associated with the main inherited cardiovascular disease and their impact on clinical management.
“It should be noted that key disease genes are always emerging as well as being “demoted”, so disease gene lists are often modified as new knowledge emerges.”
“It is critical that clinicians who are ordering genetic testing understand the utility and limitations of genetic testing.”
They also noted that appropriate pre- and post-test genetic counselling should accompany all cardiac genetic testing to ensure patients and their families understand the uncertainties associated with testing and the potential implications.
“Finally, it is important that any uncertain genetic testing results are reviewed over time and reappraised as new information is gathered.”
“The AHA Statement reinforces the key message that appropriate use of cardiac genetic testing will ultimately improve the care of our patients and their families with inherited cardiovascular diseases,” they concluded.