Kidneys Can Cause Heart Failure?

Researchers implicate kidney gene in increased risk of heart failure

(RxWiki News) The first-ever DNA sequence variant linked to heart failure also appears to play a role in causing the disease, according to new research from Washington University School of Medicine.

The DNA sequence variant, which is the result of a single changed letter of a DNA sequence, inhibits channels that regulate kidney function. Study leader Gerald W. Dorn II, MD, the Philip and Sima K. Needleman Professor of Medicine at Washington University School of Medicine in St. Louis said no one had previously suspected a kidney-specific gene defect could predispose individuals to heart failure.

Heart failure, usually a chronic condition, occurs when the heart can no longer pump enough blood to supply organs and the rest of the body. Heart failure may affect only one side of the heart or both. Coronary artery disease is the most common cause of heart failure in the U.S., but the condition may also follow certain illnesses or poisoning that weakens the heart muscle.

Thomas P. Cappola, MD, assistant professor of medicine at the University of Pennsylvania School of Medicine and one of the principal investigators in the study said he was surprised by the finding, but said the results indicate a good example of an unbiased approach to disease studies leading to unexpected targets.

Researchers studied three groups of Caucasian patients with heart failure and found one DNA sequence variant that was involved in making an important protein for the body in all three groups. They discovered a single change in the DNA sequence of the gene CLCNKA, which spurred a change in the protein that makes up part of the kidney channel responsible for regulating the secretion of chloride ions into urine. The change reduced the channel's ability by about 50 percent. The secretion process is an important process in maintaining proper salt and water balances in the body.

Researchers hypothesize that this reduction could cause elevated blood levels of the hormone renin, produced in the kidney. The presence of renin in the blood is the first signal in a cascade that can damage the heart and lead to heart failure.

About 1 in 5 people are at risk of developing heart failure over the course of their lives.