Providers’ interest in HAE genetic testing not matched by confidence
More education, fostering collaboration with experts may encourage testing
Most allergist-immunologists who treat people with hereditary angioedema (HAE) think genetic testing may be useful in diagnosing irregular cases, but many say they require more education to feel confident with the specifics of testing, a study reports.
“The study found that [health care providers] consider genetic testing during a diagnostic workup for HAE; however, many lack confidence in ordering and/or interpreting results,” researchers wrote.
Delivering targeted education to physicians and fostering collaboration with genetic testing experts would help lower perceived barriers to more regular testing, the scientists said. The study, “Health care providers’ experiences with genetic testing in patients at risk for hereditary angioedema,” was published in the Journal of Allergy and Clinical Immunology: Global.
Most cases of HAE are classified as type 1 or type 2. These variants are caused by mutations in the SERPING1 gene, which result in lowered activity of the protein C1 esterase inhibitor (C1-INH). Low C1-INH activity can lead to abnormally high levels of the signaling molecule bradykinin, allowing fluid from blood vessels to leak into nearby tissues and cause swelling attacks.
Testing C1-INH levels and activity is the most common way to diagnose HAE. In a small subset of cases, however, there are no mutations in the SERPING1 gene and C1-INH activity is normal. These are sometimes referred to as HAE type 3 and are more challenging to diagnose. When C1-INH levels are normal, but physicians suspect HAE, genetic testing may be needed to confirm a diagnosis.
Allergist-immunologists, who manage most HAE cases, may lack detailed practical information about how to order genetic tests and aren’t always trained in how to interpret their results. “These barriers can be easily addressed via continuing education offerings and consultation with medical genetic experts; however, to understand and address the needs of practicing allergist-immunologists, the educational gaps must be identified,” the researchers wrote.
Barriers to genetic testing
To assess the concerns of health care providers, the scientists surveyed 54 allergist-immunologists who manage people with HAE. The survey asked about the physicians’ opinions of genetic testing in possible cases of HAE and their comfort level in ordering and interpreting those tests.
Almost all (92.7%) respondents who responded about the helpfulness of genetic testing said they believe it’s “probably or definitely helpful” in diagnosing HAE. Most (77.8%) said they usually use genetic testing in patients with recurring angioedema after other tests prove inconclusive.
Many of the allergist-immunologists didn’t feel entirely comfortable ordering and interpreting genetic tests, however. Only 30% said they were extremely confident ordering genetic testing and just 15% said they were extremely confident interpreting the results. The remainder were somewhat confident, felt neutral, or were somewhat uncomfortable.
“Current medical education curricula often do not provide detailed practical knowledge on the ordering and interpretation of genetic testing,” the researchers wrote, adding this may explain their lack of comfort with testing.
Top concerns about ordering tests were the cost and uncertainty about insurance. At some clinical practices, genetic counselors weren’t available to help interpret the results. Other providers were unsure which tests to order or weren’t convinced the tests would be useful.
Identifying these concerns is an important first step toward helping physicians feel more confident with genetic testing, said the researchers, who suggested that education efforts for health care providers and sponsored programs to make testing more accessible should be considered. They also suggested that genetic counselors, who specialize in interpreting the results of genetic tests, should be integrated into practices that manage HAE patients.
“Collaborations between geneticists and allergist-immunologists should be fostered, as the combination of both specialties is particularly important for cascade testing subsequent to identification of a pathogenic [disease-causing] family variant associated with HAE,” they wrote.
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