REYKJAVIK, Iceland,
March 6, 2011 /PRNewswire-FirstCall/
-- Scientists at deCODE genetics and academic colleagues from
Iceland, The Netherlands, Denmark, USA
and Illumina, Inc., today report the discovery of single-letter
variants (SNPs) in the sequence of the human genome associated with
high risk of sick sinus syndrome (SSS). The study is published
today in the online edition of Nature Genetics.
The study reports a genetic variant in the gene MYH6 that is
associated with high risk of sick sinus syndrome (SSS) in
Icelanders. The lifetime risk of being diagnosed with SSS is about
6% for individuals without this genetic variant but is increased by
12.5 times, to approximately 50%, for those that carry the variant.
SSS is a heart rhythm disorder that is characterized by an
inappropriately slow heart rate. It is commonly seen in the elderly
and many with SSS eventually need a permanent pacemaker.
With the aim of searching for sequence variants that predispose
to SSS, a genome-wide association study was performed including 792
Icelanders with SSS and 37,592 Icelandic controls. The study
utilized SNP data from several sources including Illumina SNP chip
genotyping as well as whole-genome sequencing of 7 Icelanders with
SSS and 80 Icelanders not diagnosed with SSS. The whole-genome
sequencing data yielded a strong association between SSS and a rare
missense mutation in MYH6 that could not be accounted for by any
other sequence variation. MYH6 encodes one form of myosin, a major
component of the contractile system of the heart, and was recently
associated with the function of the conduction system of the heart
by studies from deCODE and others. This is the first time that MYH6
is implicated in the development of heart rhythm disorders.
"This work constitutes our first entry into the study of rare
variants in common diseases that confer large risk of disease. It
is clear that the risk of common diseases in our society is
accounted for by both common and rare variants in the sequence of
the genome. We here at deCODE and scientists all over the world
have over the past few years discovered large numbers of common
variants that confer risk of common diseases. Now we are entering
into the era of rare variants that are providing us with clear
insights into the pathogenesis of diseases and possibilities of
putting together very effective diagnostics" said Kari Stefansson, deCODE's CEO and senior author
of the study.
The paper, "A rare variant in MYH6 is associated with high risk
of sick sinus syndrome" is published online in Nature Genetics at
http://www.nature.com/ng and will appear in an upcoming print
edition of the journal.
Sick sinus syndrome (SSS), or sinus node dysfunction, is a
common clinical disorder that is characterized by pathological slow
heart rate, sinus arrest and/or attenuated heart rate response to
exercise. The syndrome comprises a wide range of
electrophysiological abnormalities, including failure of the sinus
node and atrial impulse formation or propagation, as well as
susceptibility to atrial tachyarrhythmias, particularly atrial
fibrillation. Although encountered at any age, SSS is primarily a
disease of the elderly and is often secondary to other cardiac
disorders when diagnosed in younger individuals. Symptoms are often
intermittent and/or nonspecific and include dizziness, syncope and
heart failure. The only effective treatment for symptomatic and
irreversible sinus node dysfunction is permanent cardiac pacing,
and SSS remains the most common indication for permanent pacemaker
implantation.
About deCODE
Headquartered in Reykjavik,
Iceland, deCODE genetics is a global leader in analyzing and
understanding the human genome. Using its unique expertise and
population resources, deCODE has discovered key genetic risk
factors for dozens of common diseases ranging from cardiovascular
disease to cancer. deCODE employs its capabilities to develop
DNA-based tests and personal genome scans to better understand
individual risk and empower prevention. It also licenses its tests,
intellectual property and analytical tools to partners, and
provides comprehensive genotyping, sequencing and data analysis
services to companies and research institutions around the globe.
Through its CLIA- and CAP-certified laboratory deCODE offers
DNA-based tests for gauging risk and empowering prevention of
common diseases, including deCODE Glaucoma(TM); deCODE T2(TM) for
type 2 diabetes; deCODE AF(TM) for atrial fibrillation and stroke;
deCODE MI(TM) for heart attack; deCODE ProstateCancer(TM); and
deCODE BreastCancer, for the common forms of breast cancer. Through
its pioneering personal genome analysis service deCODEme(TM),
deCODE enables individuals to better understand their risk of
dozens of common diseases and to learn about their ancestry and
other traits. Visit us on the web at http://www.decode.com; at
http://www.decodehealth.com; at http://www.decodeme.com; and on our
blog at http://www.decodeyou.com.
Contact:
Gisli Arnason
+354-570-1825
gisli.arnason@decode.is
SOURCE DeCODE Genetics Inc