Genetic testing and counselling for inherited cardiovascular diseases may help patients and their families make informed decisions about managing their heart health, according to Genetic Testing for Inherited Cardiovascular Diseases, a scientific statement from the American Heart Association (AHA), published today in the Association’s journal Circulation: Genomic and Precision Medicine.
The statement summarises existing knowledge about the genes or combination of genes that may influence inherited heart diseases and also provides suggestions for best practices for genetic testing.
“Although genetic testing has seen explosive growth in the past few years, both in the clinical setting and with direct-to-consumer testing, genetic testing for heart disease should be reserved for specific patients,” said Kiran Musunuru, chair of the writing group for the scientific statement and professor of cardiovascular medicine and genetics at the Perelman School of Medicine at the University of Pennsylvania, Philadelphia, USA.
According to the statement, cardiovascular conditions that may have an inherited genetic component include cardiomyopathies, thoracic aortic aneurysms and dissections, arrhythmic disorders and familial hypercholesterolemia.
The scientific statement suggests that before considering genetic testing, a healthcare provider should work with the patient to document their family medical history, ideally, going back three generations, to determine if there is a pattern of certain types of heart disease.
It notes that genetic testing should typically be reserved for patients with a confirmed or suspected diagnosis of an inherited cardiovascular disease or for individuals at high risk due to a previously identified disease-causing variant (a gene abnormality that is different from most humans, often responsible for the clinical disease in question) in their family.
Genetic counselling is “essential” before genetic testing to educate patients on the process and potential results, as well as the potential risks and uncertainties related to testing. Counselling is also critical after genetic testing the scientific statement notes, so the counsellor can explain the results and potential consequences for the patient’s health and the health of family members including children.
Since immediate family members—first-degree relatives such as fathers, mothers, siblings or children—might share genetic variants predisposing them to an inherited cardiovascular disease, they are considered to be at higher risk for the same conditions, AHA suggests. Once a genetic variant is identified within a family, all first-degree relatives should consider undergoing genetic testing and counselling for that specific mutation whenever possible.
“With most genetic cardiovascular diseases, inheriting a mutation (or variant) from a parent substantially increases the risk of getting the disease but does not guarantee the disease,” said Musunuru. “In some cases, it might be possible to act early and prevent the disease. In other cases, having the mutation for a genetically caused cardiovascular condition might lead to different and possibly more aggressive treatment.”
Advances in human genetics are improving the understanding of a variety of inherited cardiovascular diseases, AHA noted in a press release, adding however, that there are still limitations. Genetic testing might not reveal a cause or confirm a diagnosis of the patient’s disease.
“Another issue is that we have not yet clarified the full spectrum of genes that are responsible for various inherited cardiovascular diseases—we are still very much in discovery mode, with ongoing research efforts,” added Musunuru. “Genetic testing methods are evolving, and reliable classification of variants identified in genetic testing will remain a preeminent challenge for the practice of clinical genetics.”
The statement was written on behalf of the AHA’s Council on Genomic and Precision Medicine; Council on Arteriosclerosis, Thrombosis and Vascular Biology; Council on Cardiovascular and Stroke Nursing; and Council on Clinical Cardiology.
Co-authors and members of the writing committee are Ray E Hershberger (Columbus, USA), Sharlene M Day (Philadelphia, USA), N Jennifer Klinedinst (Baltimore, USA), Andrew P Landstrom (Durham, USA), Victoria N Parikh (Stanford, USA), Siddharth Prakash (Houston, USA), Christopher Semsarian (Sydney, Australia), and, Amy C Sturm (Columbus, USA). Author disclosures are in the manuscript.