Genetic markers may predict when heart disease patients are likely to have heart attacks

April 2, 2014

Researchers at the Intermountain Medical Center Heart Institute in Murray, Utah, have identified a biological process that may help physicians predict when someone with heart disease is likely to have a heart attack in the near future. A new study by the team has identified plasma levels of two markers—microRNA 122 and 126—that appear to decline a few days before a person suffers a heart attack.

The discovery of the diminishing microRNA markers began with the understanding of a basic process known as the central dogma. DNA contains the genetic information an organism uses to grow and develop. Messenger ribonucleic acid (mRNA) communicates this information to the rest of the body and translates the genetic information into protein (gene expression).

In 1993 scientists discovered that small forms of RNA didn’t follow standard translation patterns. These forms, microRNA, weren’t making proteins, but rather were interfering with mRNA to prevent translation. At the same time, physicians at the Intermountain Medical Center Heart Institute created the Intermountain Heart Study Registry, which includes blood samples from a large number of heart patients.

Researchers looked at samples in the registry from 30 patients who had suffered a heart attack within 44 days of having their blood collected. They noticed that within two weeks of experiencing a heart attack, patients’ microRNA 122 and 126 dramatically dropped. They concluded that something about these microRNAs being present and interrupting the translation process prevents people with heart disease from having a heart attack.

Says lead researcher Oxana Galenko, DBMSC: “MicroRNAs turn things off. Whatever they usually turn off in people with heart disease before a heart attack isn’t being turned off when microRNA levels are reduced, which may be causing something else to be activated. When their levels are reduced, heart disease takes a turn for the worse and heart attacks are likely to occur.”

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