August 11, 2023

COLUMBUS, Ohio – Patients of African ancestry with dilated cardiomyopathy (DCM) are less likely to have clinically actionable variants in DCM genes than those of European ancestry, even though they and their family members are at greater risk for the heart muscle disease, according to a study led by researchers at The Ohio State University Wexner Medical Center and College of Medicine
The reasons may be because of differences in the types of variants found in DCM patients of African ancestry when compared to European and a lack of representation of African ancestry patients in clinical trials. 
“Understanding the underlying genetic characteristics and contributions to DCM is important to determining why and how it develops, which can lead to improved individualized approaches to precision medicine care and development of targeted therapies,” said first author Elizabeth Jordan, a licensed genetic counselor and associate professor of clinical internal medicine at Ohio State. The research was published in the Journal of the American Medical Association.
DCM is a condition in which the heart muscle weakens and the left ventricle enlarges. It’s the most common cause of patients needing a heart transplant and is responsible for up to half of the heart failure cases that result from a weakened left ventricle. 
In the study of 1,198 patients, researchers found 8.2% of DCM patients of African ancestry had a clinically actionable variant, commonly known as mutation, compared to 25.5% of patients of European ancestry.
The data was collected over four years at 25 leading academic U.S. heart failure/heart transplant programs that are part of the Dilated Cardiomyopathy Consortium, led by Ray Hershberger, MD, a cardiologist and division director of human genetics at Ohio State. He said the study highlights how a lack of representation from minority groups has hindered progress in genomic medicine.
“What we know about the genetics of DCM has largely come from patients of European ancestry. Researchers need to prioritize diversity of participants, especially Black patients, in genetic studies in order to more fully understand the genetics of DCM,” said Hershberger, senior author and a researcher at the Dorothy M. Davis Heart and Lung Research Institute
Previous research by the consortium found that Black patients diagnosed with DCM of unknown cause are more likely to have family members at risk of developing it. Because some patients are asymptomatic for months or years until severe disease like heart failure develops, experts recommend cardiovascular screening of first-degree family members (children, siblings or parents) of patients with DCM. 
“Participation of individuals of diverse racial and ethnic backgrounds, particularly individuals who identify as Black in the United States, is made challenging by an ingrained distrust of the research and medical communities. This is in part due to historic and ongoing misconduct in the treatment of minority populations and inequities ingrained in the healthcare system. This pattern was also previously evaluated in our study population, which showed lower genome-sequencing knowledge and lower levels of trust in researchers reported by participants identifying as Black relative to white,” said Daniel Kinnamon, co-first author and assistant professor and director of Human Genetics Research Informatics at Ohio State.
The Dilated Cardiomyopathy Consortium is funded by a $12.4 million grant from the National Heart, Lung, and Blood Institute of the National Institutes of Health and a supplemental grant from the National Human Genome Research Institute. 
Media contact: Amy Colgan, Wexner Medical Center Media Relations,

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