Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Tachycardia: Genetic Cause Discovered

31.07.2013
Ventricular fibrillation, loss of consciousness and death in seemingly healthy people: These are the characteristics of the so-called Brugada syndrome. In the search for the causes of this disease, an international team of scientists has now discovered a surprising fact.

A gene known to be essential in the formation of the interventricular septum and of the cardiac valves can be responsible for the development of the Brugada syndrome.

This is the main result of a study recently published in the journal Nature Genetics by the research group of Amsterdam cardiologist Connie R. Bezzina. The study also involved scientists at the Biocenter of the University of Würzburg: Professor Manfred Gessler, head of the Department for Developmental Biochemistry, and his team have been studying the respective gene, the Hey2 gene, for a long time.

Gessler and his associates identified the Hey2 gene more than ten years ago. In their studies, they were also able to show in an animal model that the gene plays a significant role in the formation of the interventricular septum and of the cardiac valves. "However, the fact that the gene is involved in the electrical activity of the cardiac muscle and conduction cells has not been shown before," says Gessler.

The Brugada syndrome

The Brugada syndrome has been recognized for only just about 20 years as a distinct genetic arrhythmia of the heart. It was first described in 1991 by two brothers, Josep and Pedro Brugada. Patients suffering from this disease are affected by an abnormal electrical conduction in the heart associated with a high risk of sudden cardiac death. They are subject to recurrent cardiac arrhythmias, which can lead to loss of consciousness. In the worst case, ventricular fibrillation occurs when the ventricles of the heart contract so rapidly that they cease to pump the blood effectively, which results in cardiovascular failure.

"Previously, it was known that about 20 percent of the patients have defects in the sodium ion channel of the cardiac cells, predominantly in the subunit encoded by the SNC5A gene. However, the causes of the disease remained unclear in the majority of cases," says Manfred Gessler.

The study

In the search for further risk factors, the study group of Connie R. Bezzina first conducted genome-wide association studies, involving more than 1000 patients. As expected, they found that the disease is correlated with certain genetic variants of the SCN5A gene and of the related SCN10A gene, which both have a function in cardiac excitation propagation. The scientists confirmed this finding in further patient cohorts.

To the researchers’ surprise, however, the first analysis also revealed statistically significant data indicating that genetic variations near the HEY2 gene play a role in the development of the Brugada syndrome. These results were confirmed in additional patient cohorts as well.

Defects in the Hey2 gene identified

In a joint project with the Amsterdam study group, the Würzburg researchers then achieved a major breakthrough: "With the help of special optical methods, we were able to establish that mice lacking one of the two copies of the Hey2 gene also exhibit detectable changes to the ventricular excitation propagation and the subsequent repolarization of the cardiac muscle cells comparable to those of the Brugada syndrome," Gessler explains. Hence, the HEY2 gene, previously only linked to developmental defects of the heart, also seems to have an impact on the correct formation of the cardiac conduction system and the electrical excitability of the cardiac muscle cells.

Further studies are already in progress in order to shed more light on the molecular mechanisms of this defect.

Common variants at SCN5A-SCN10A and HEY2 are associated with Brugada syndrome, a rare disease with high risk of sudden cardiac death; Connie R Bezzina et al. Nature Genetics, published online 21 July 2013; doi:10.1038/ng.2712

Contact person

Prof. Dr. Manfred Gessler, T: +49 (0)931 31-84159,
email: gessler@biozentrum.uni-wuerzburg.de

Gunnar Bartsch | Uni Würzburg
Further information:
http://www.uni-wuerzburg.de

More articles from Health and Medicine:

nachricht Cholesterol-lowering drugs may fight infectious disease
22.08.2017 | Duke University

nachricht Once invincible superbug squashed by 'superteam' of antibiotics
22.08.2017 | University at Buffalo

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

What the world's tiniest 'monster truck' reveals

23.08.2017 | Life Sciences

Treating arthritis with algae

23.08.2017 | Life Sciences

Witnessing turbulent motion in the atmosphere of a distant star

23.08.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>