EU research identifies gene linked with irregular heartbeat A partially EU-funded team of researchers has identified the location of a gene that may have an important influence on the risk of atrial fibrillation (irregular heartbeat). The study was published in the journal Nature Genetics. The researchers hope their findings will lead ... A partially EU-funded team of researchers has identified the location of a gene that may have an important influence on the risk of atrial fibrillation (irregular heartbeat). The study was published in the journal Nature Genetics. The researchers hope their findings will lead to the development of new and more specific drugs for the treatment of atrial fibrillation. The study was part of two EU-funded projects: ECOGENE ('Unlocking the European Union convergence region potential in genetics'), and OPENGENE ('Opening Estonian genome project for European Research Area'), which received EUR 1.09 million and EUR 1.33 million respectively under the Regions of Knowledge budget line of the Seventh Framework Programme (FP7). Irregular heartbeat is not a seriously life-threatening condition, but it increases the risk of developing more serious diseases such as stroke, dementia and cardiac insufficiency. There are also important economic factors to consider as it is believed to affect up to 600 million people worldwide. The aim of the researchers was to uncover the genetic factors that contribute to atrial fibrillation. The gene locus was identified through a large-scale analysis of data from 10 epidemiological studies which involved comparing the genomes of 1,335 patients suffering from atrial fibrillation with those of a control group. The atrial fibrillation patients showed a particular form of the condition known as lone atrial fibrillation, which is unusual because it tends to occur before 65 years of age and does not appear to be associated with any particular changes in heart structure. 'The homogeneous nature of this group of patients allowed us to identify a gene called KCNN3 which markedly influences risk for atrial fibrillation, ' said Research leader Dr Stefan Kääb, from Germany's Ludwig-Maximilians-Universität München (LMU). 'Interestingly, it turns out that this gene is required for the synthesis of the potassium channel, a protein that regulates the flow of potassium ions across cell membranes. The protein participates in the conduction of electrical impulses in the heart and therefore represents a promising new drug target.' He continued, 'Our results improve our understanding of the pathophysiological mechanisms that contribute to the manifestation of atrial fibrillation. We also hope that in the longer term they will allow us to predict individual levels of risk.' In order for the body to function properly, the heart must pump an adequate supply of blood to all vital organs. It does this by contractions of the atria and the ventricles in a strict sequence. The sequence is controlled by electrical signals that are initiated by the sinus node (a pacemaker tissue in the right atrium of the heart). Irregular heartbeat occurs when the sinus node fails to work properly. 'Atrial fibrillation can give rise to more serious conditions - principally as a result of the fact that the blood is not completely expelled from the heart, and this facilitates the formation of thromboses,' explained Dr Kääb. 'These in turn can precipitate strokes or an embolism - the complete obstruction of a blood vessel. Atrial fibrillation also increases the risk of cardiac insufficiency, which may result in reduction of brain function and ultimately dementia.' In two previous studies, the team identified a total of nine genes that affect the duration of part of the heart's contraction cycle and also modulate risk of atrial fibrillation. In the current study, researchers from LMU worked with the Technical University of Munich, the Helmholtz Center and 50 other international research institutions from Estonia, Iceland, the Netherlands, and the US. Countries Germany, Estonia, Iceland, Netherlands, United States
