An underdiagnosed genetic mutation in people of African descent carries an increased risk for heart failure, according to a new study.

When present in those patients, a genetic variant, TTR V122I, could lead to a higher risk of hereditary transthyretin amyloid cardiomyopathy — a potentially fatal disease caused by a protein buildup in the heart. Researchers at Mount Sinai School of Medicine and the University of Pennsylvania School of Medicine published the study in the Journal of the American Medical Association.

Heart disease is a leading cause of death among all genders and racial and ethnic groups, but non-Hispanic black people are more than twice as likely to die of heart disease, according to the Centers for Disease Control and Prevention. The discovery underscores the need to study nonwhite populations and their health concerns, clinicians say.

Heart failure, a condition in which the heart doesn’t pump blood well enough to meet the needs of the body, can result from other forms of heart disease, the Mayo Clinic said.

Researchers analyzed the connection between the genetic mutation and heart failure in 9,694 people of African and Latino ancestry. The Latino participants were mainly people from Afro-Caribbean populations, said Ron Do, one of the researchers at the Icahn School of Medicine at Mount Sinai.

Do and his colleagues found that 44% of people older than 50 had the mutation and heart failure. But 11% of those with the mutation and heart failure had hereditary transthyretin amyloid cardiomyopathy. Because it takes about three years to have the condition diagnosed, researchers believe it could be underdiagnosed or not diagnosed soon enough.

Researchers also noticed in young carriers of the mutation a thickening of the left ventricular wall that could be an early indicator of heart failure. Those patients didn’t show an obvious sign of heart failure, but a thickening of the left ventricular wall, the heart’s main blood pumping chamber, can result in an inability to push blood with enough force.

That discovery suggests that slight changes in the heart could be happening years before patients and doctors see overt signs of diseases.