Heart rhythm gene revealed in new research

Study shows gene linked to heart rhythm problems, including ventricular fibrillation - <em>News Release</em>

Imperial College London News Release

Under strict embargo until:
18.00 GMT (13.00 ET)
Sunday 10 January 2010

A gene that regulates the rhythm of the heart is revealed in new research published today in Nature Genetics. The authors of the study, from Imperial College London, say their discovery helps them to understand how the body's heartbeat is controlled and could ultimately help scientists design more targeted drugs to prevent and treat certain heart problems.

Heart disease is the leading cause of death in the world, accounting for almost seven million deaths per year. Over half of these deaths are sudden and caused by serious heart rhythm disturbances such as ventricular fibrillation. The gene identified in today's study is linked to these heart rhythm disturbances and reveals a new mechanism that controls the heartbeat.

A person's heartbeat is controlled by electrical signals, which start in one central place - the heart's pacemaker - and travel around the heart muscle. This electrical signal is transmitted by specialised proteins in heart muscle cells called ion channels. Today's study reports the discovery of a new ion channel in the heart called SCN10A, which directly influences heart rhythm disturbances and a person's risk of cardiac arrest caused by ventricular fibrillation.

The mutation identified in the SCN10A gene is common and, at an individual level, has a modest effect on a person's risk of having heart rhythm problems. Further research is needed to determine what other mutations exist in this gene, and whether these might variants might have a stronger effect.

The authors of the study, funded by the Wellcome Trust, BBSRC and the British Heart Foundation, hope their findings will enable scientists to develop new ways to prevent and treat heart rhythm disturbances.

Dr John Chambers, lead author of the study from the School of Public Health at Imperial College London, said: "Genetic variation is like the two sides of a coin. One side is associated with increased risk, the other with decreased risk. We have identified a gene that influences heart rhythm, and people with different variants of the gene will have increased or decreased risks of developing heart rhythm problems.

The researchers identified the new gene by analysing people's electrocardiogram readings

"Though the gene variant itself may only have a small effect on a person's risk of having heart rhythm problems, our study gives us important new insight into the mechanisms affecting disordered heart rhythm," added Dr Chambers.

Professor Jaspal S Kooner, corresponding author of the study from the National Heart & Lung Institute at Imperial College London, said: "These results may enable us to predict and diagnose serious heart rhythm disturbances better, and in the future develop improved treatments for preventing ventricular fibrillation, which is a leading cause of death worldwide."

In today's study, the researchers analysed the genetic make-up of almost 20,000 people to look for genetic factors influencing the heartbeat. They studied the electrocardiogram (ECG, a recording of the heartbeat) of each person, and measured the time taken for electrical signals to travel to different parts of the heart. The researchers discovered that variation in the gene that encodes the ion channel SCN10A was associated with slow and irregular heart rhythms, including risk of ventricular fibrillation.

The researchers then identified the protein in human and mouse heart muscle cells. Although scientists had previously discovered the protein in nerve cells, this is the first time it has been identified in heart muscle cells.

The scientists then tested their findings by comparing the heart rhythm of mice with and without the SCN10A gene. The results showed that mice without a functioning SCN10A gene had shortened heartbeats, providing confirmation that the gene regulates heart rhythm.

Professor Peter Weissberg, Medical Director at the British Heart Foundation, said: "These findings are important and exciting. By looking at how differences in our genes are linked to differences in our heartbeat, this research has discovered that a single letter change in a gene can make some people more prone to heart rhythm disturbances. Before this, we didn't even realise that the protein produced by this gene was present in heart cells - now it looks like it could be a target for drug development to prevent life-threatening heart rhythm problems. Importantly, because this study was performed in a predominantly UK Indian Asian community and verified in white Europeans, we can be sure that the finding is relevant to most of the UK population. We're proud to have funded much of the research that led to this breakthrough."

Professor Douglas Kell, BBSRC Chief Executive, said: "Having an understanding of the genetics behind a healthy heart gives us access to appreciating what has gone wrong when a person's cardiovascular health suffers. This research gives us part of a very complicated picture of how the heart works on a molecular level."

-Ends-

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Notes to Editors:

"Genetic variation in SCN10A influences cardiac conduction and risk of ventricular fibrillation" Nature Genetics, Sunday 10 January 2010.
Corresponding authors: Dr John Chambers and Professor Jaspal Kooner, Imperial College London
(For a full list of authors, please see paper)

2. About Imperial College London

Consistently rated amongst the world's best universities, Imperial College London is a science-based institution with a reputation for excellence in teaching and research that attracts 14,000 students and 6,000 staff of the highest international quality.

Innovative research at the College explores the interface between science, medicine, engineering and business, delivering practica l solutions that improve quality of life and the environment - underpinned by a dynamic enterprise culture.

Since its foundation in 1907, Imperial's contributions to society have included the discovery of penicillin, the development of holography and the foundations of fibre optics. This commitment to the application of research for the benefit of all continues today, with current focuses including interdisciplinary collaborations to improve health in the UK and globally, tackle climate change and develop clean and sustainable sources of energy.

Website: www.imperial.ac.uk

3. About BBSRC

The Biotechnology and Biological Sciences Research Council (BBSRC) is the UK funding agency for research in the life sciences. Sponsored by Government, BBSRC annually invests around £450 million in a wide range of research that makes a significant contribution to the quality of life for UK citizens and supports a number of important industrial stakeholders including the agriculture, food, chemical, healthcare and pharmaceutical sectors. BBSRC carries out its mission by funding internationally competitive research, providing training in the biosciences, fostering opportunities for knowledge transfer and innovation and promoting interaction with the public and other stakeholders on issues of scientific interest in universities, centres and institutes.

The Babraham Institute, Institute for Animal Health, Institute of Food Research, John Innes Centre and Rothamsted Research are Institutes of BBSRC. The Institutes conduct long-term, mission-oriented research using specialist facilities. They have strong interactions with industry, Government departments and other end-users of their research.

For more information see: http://www.bbsrc.ac.uk

4. The Wellcome Trust is the largest charity in the UK. It funds innovative biomedical research, in the UK and internationally, spending over £600 million each year to support the brightest scientists with the best ideas. The Wellcome Trust supports public debate about biomedical research and its impact on health and wellbeing. http://www.wellcome.ac.uk

5. The British Heart Foundation (BHF) is the nation's heart charity, dedicated to saving lives through pioneering research, patient care, campaigning for change and by providing vital information. But we urgently need help. We rely on donations of time and money to continue our life-saving work. Because together we can beat heart disease. For more information visit www.bhf.org.uk/pressoffice