Why every heart is different

Researchers are discovering relationships between gene variants and cardiac function

Vital Muscle: The heart pumps oxygenated and nutrient-rich blood through our bodies. © Sergey Nivens / thinkstock
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Strong or weak, big or small: Minimal changes in the genetic material determine how our heart beats and is shaped. Scientists have now discovered ten previously unknown genetic factors associated with the structure and function of the pump organ. From the results they hope for new approaches for the prevention and treatment of cardiovascular diseases.

Our heart is in constant use throughout life: every day it beats 100, 000 times to provide the body with oxygenated and nutrient-rich blood. It is the engine without which our organism does not work. In old age the heart becomes smaller and weaker. But his function can be disturbed even at a young age. For example, if the heart is limp in the case of heart failure, sufferers can quickly feel it in everyday life.

But what factors determine whether our pump organ beats powerfully or is prone to it, whether it's heavy or easy, big or small? Scientists led by Philipp Wild of the Mainz University Medical Center have now devoted themselves to this question on a genetic level - identifying ten new variants in the genome that are related to the structure and function of the heart.

Tested on heart and genes

For their study, the researchers evaluated 30 studies with a total of 46, 533 subjects predominantly of European descent. They analyzed information such as the mass of the heart chambers or functional measurements of the pumping behavior. "We looked at each individual value to see if there were hereditary variants associated with it and re-examined the results from the initial analysis on other groups, " says Wild. Looking into the genome, the team focused on so-called single nucleotide polymorphisms, SNPs for short - typical variations in the genome, in which only a single building block is altered.

In fact, Wild and his colleagues discovered ten previously unknown hereditary factors: seven of them are related to the size of the aortic root, the part of the large body artery that exits directly from the left ventricle. In addition, the researchers discovered two new genetic variants associated with the diameter of the left ventricle. Another hereditary factor is related to the filling behavior of the left ventricle. This can be disturbed, for example, during a heart failure. display

Approaches to new therapies?

For other heart parameters examined, however, the scientists found no genetic variants. "There can be different reasons. Either the genetic influence is so low that it was not discovered, or it is because we have focused only on known SNPs and have not studied the whole genome. Having found nothing does not mean that there is no genetic influence, "says co-author Marcus D rr of the German Center for Cardiovascular Research in Greifswald.

Further studies are now to clarify how exactly the discovered hereditary changes in the construction and function of the heart have a say. These results could help understand the complex pattern of genetic and environmental factors that underlie cardiovascular disease - and thus provide new opportunities for prevention and therapy Open, hopes the team. (The Journal of Clinical Investigation, 2017; doi: 10.1172 / JCI84840)

(German Center for Cardiovascular Research eV, 11.05.2017 - DAL)