deCODE Discovers Second Common Genetic Risk Factor for Atrial Fibrillation and Stroke. Will be integrated into deCODE AF™ DNA-based risk assessment test, and into the deCODEme™ and deCODEme Cardio™ scans.

Scientists at deCODE genetics and colleagues from Europe and the United States today report the discovery of a common single-letter variant in the sequence of the human genome (SNP) conferring increased risk of atrial fibrillation (AF) and stroke. The findings will be integrated directly into the deCODE AF™ reference laboratory test for gauging individual risk of AF and stroke and helping to identify stroke patients who may benefit from enhanced monitoring for AF. The study is published online today in Nature Genetics.

The new SNP is in the ZFHX3 gene on chromosome 16q22, and the more than one third of people of European descent who carry one copy are at approximately 20% greater risk of AF and cardioembolic stroke than are individuals who carry none. AF is the most common type of cardiac arrhythmia, and is a major risk factor for stroke. Because AF is often intermittent and difficult to detect, gauging genetic susceptibility can help doctors to decide which of their stroke patients might benefit from longer-term monitoring for AF following a stroke. Those with stroke due to AF may be given different therapy than they would otherwise. This is the purpose of deCODE AF™, at the heart of which is the major AF and stroke variant discovered by deCODE on 4q25. Indeed today’s findings are the result of deCODE’s program to build on this work and to find new risk variants. After expanding their genome-wide association study in Iceland, the deCODE team took the top SNPs outside the 4q25 region and typed them in case-control cohorts from Iceland, Norway and the United States. This confirmed the ZFHX3 SNP as a risk variant for AF. Analysis in stroke cohorts from Iceland, Germany, Sweden and the UK demonstrated that this SNP was associated with increased risk of stroke, particularly cardioembolic stroke.

“This is an important discovery and all the more gratifying because we can integrate it straight into a test that is already helping to improve patient care in the clinic.
As with our 4q25 variant, this latest discovery has been replicated in numerous populations by us and others, and the connection to cardioembolic stroke is yet further evidence that we are putting our finger on an important pathway involved in AF and stroke risk. The ability to routinely test for these risk factors means that we can understand whom we should screen intensively for AF and then prescribe the drugs most suited to the cause of a particular patient’s disease. This is the sort of personalized medicine that genetics is enabling – individualized care that may mean not only better outcomes but significant potential savings to the healthcare system. Discoveries like this are the foundation upon which this transformation is being made,” said Kari Stefansson, CEO of deCODE.

deCODE and the authors wish to thank the participants who took part in this study and made it possible. Financial support for this study was provided by US National Institutes of Health grants HL075266 and U01 HL65962 and American Heart Association grant 0940116N; by the German Federal Ministry of Education and Research (01GI9909/3), by the German Migraine & Headache Society (DMKG), and by unrestricted grants of equal share from Astra Zeneca, Berlin Chemie, Boots Healthcare, Glaxo-Smith-Kline, McNeil Pharma, MSD Sharp & Dohme and Pfizer to the University of Muenster.

Click on the image to watch the 60 Minutes Australia segment on genetic testing

The Killer In You

60 Minutes Australia recently visited the deCODE genetics labs in Iceland and interviewed deCODE’s CEO Dr. Kari Stefansson. Among the people who did the deCODEme genetic test were journalist Liz Hayes, world surfing champion Layne Beachley and Australian television’s favorite builder, Scott Cam. To watch the 60 Minutes Australia segment click on the image above. To read the transcript of the webchat with Professor Bob Williamson click here. To learn more about deCODEme genetic tests and order your personal genome scan visit www.decodeme.com.

Iceland was mainly settled by Scandinavian men and women from Irealand and Scotland

In a paper published today scientists at deCODE genetics present the results of the largest study of ancient DNA from a single population ever undertaken. Analyzing mitochondrial DNA, which is passed from mother to offspring, from 68 skeletal remains from approximately 1000 years ago, the study provides the most detailed look to date at how a contemporary population differs from that of its ancestors. The results confirm previous deCODE work that used genetics to test the history of Iceland as recorded in the sagas.

Audio link:  Dr. Kari Stefansson interviewed on BBC WORLD. BBC

These studies demonstrated that the country seems indeed to have been settled by men from Scandinavia – the vikings – but that the majority of the original female inhabitants were from the coastal regions of Scotland and Ireland, areas that regularly suffered raids by vikings in the years around the settlement of Iceland 1100 years ago.

Perhaps the most remarkable finding of the study published today is that the gene pool of contemporary Icelanders appears to have evolved rapidly over the intervening thousand years. As a result, the original female settlers are genetically more closely related to the present day populations of Scotland, Ireland and Scandinavia, as well as those of northwestern Europe and even southwestern Europe, than they are to present day Icelanders. This is an important demonstration of a phenomenon known as ‘genetic drift.’ In essence, in any population certain individuals will have more offspring and, by chance and in this case over the course of 35 generations, many more descendants than others. And as a result, particularly in a small population, the genetic variety of the original population can decrease and change over time. In this study only mitochondrial DNA was studied, but the same phenomenon applies to the Y chromosome, which is passed from fathers to sons, and to any other part of the genome. The paper, ‘Sequences from first settlers reveal rapid evolution in Icelandic mtDNA pool,’ is published today in the open-access journal PLOS Genetics.

“This study is a major contribution to the use of ancient DNA studies in tracing the history not just of single populations, but of our species and how we spread from Africa to every corner of the globe. It is the first such study to be large enough to permit meaningful statistical methods to be applied to ancient DNA. We very much hope this will aid and encourage others to follow with large studies in other parts of the world. In this field, as in the genetics of common diseases, we are pleased and proud to be able to put the knowledge we gain in Iceland to work for the benefit of people everywhere,” said Kari Stefansson, CEO of deCODE.

Icelandic handball team celebrates silver at the Olympics

Icelandic handball has never enjoyed such a high profile in the US press, and deservedly so. Having just won the silver in the men’s Olympic final, Iceland is one of the smallest nations to win any kind of Olympic medal. American and European journalists and bloggers, seemingly never tired with playing up Iceland’s Viking image, appear to have hit the nail on the head this time. Perhaps it is their Viking genes! Going for gold and getting the silver was a plundering raid of a kind—in Viking terms a highly successful one. While the nation woke at dawn to watch the handball team (always affectionately referred to as ‘our boys’), Iceland’s president, Ólafur Ragnar Grímsson, and his wife, Dorrit Moussaieff, have been at the Beijing Olympics since the start, cheering the team on to victory.

Aside from her official capacity as Iceland’s first lady, Dorrit Moussaieff, who recently visited deCODE Genetics to submit a deCODEme sample of her DNA, is not shy about demonstrating that she is one of the Icelandic handball team’s staunchest supporters. Since she arrived in Beijing for the opening ceremony, she has taken on various roles, from waving the Icelandic flag to assisting the team’s physiotherapist. After the Icelanders beat the Spaniards, her husband said this was the finest hour in the history of Icelandic sport and his wife went one further, insisting that Iceland was not a small country, but one of the ‘biggest in the world’—a phrase that melted the nation’s heart.

No one really expected Iceland to get this far in the competition, except perhaps the Icelanders themselves. Like their forefathers, the Vikings, they struck quickly and relied on a relentless attack while the French were more stoic and concentrated first on bolstering their defenses. In the end, the result was fair and the French deserved to win, but the Icelanders were far from deflated. Indeed, they roared and shouted on the podium as if they had won—and with good cause. In the per capita world at what the Belfast Telegraph has dubbed ‘the alternative Olympics’, a silver medal for a nation of less than 300,000 puts Iceland ahead of Bahrain and Trinidad and Tobago and only one place behind the winners Jamaica at the end of 2008 games.

Link: The New York Times – In Handball, Iceland Will Try For Its First Olympic Title
Link: USA Today – Iceland eyes gold medal in handball
Link: Washington Post – A Morning Jolt of Icelandic Team Handball
Link: Washington Post – Scenes From Iceland’s Handball Triumph
Link: Washington Post – Icelandic Handball’s Finest Moment
Link: Washington Post – Icelandic Handball: Magic Elves, Cured Shark and Existentialism

A look at deCODE, the biotech company in Iceland that is researching genes for common conditions like heart disease, stroke and cancer. Sue Herera interviews NBC’s Robert Bazell on his coverage of deCODE and discusses the scientific, pharmacological and commercial implications of genetic testing.

Originally broadcast July 22, 2008.

Link: Watch the interview.