deCODE genetics and Roche Diagnostics announced a landmark discovery under their alliance to develop DNA-based diagnostic tests for common diseases. deCODE scientists have identified forms of a gene that confer approximately twice the average risk of myocardial infarction, or heart attack.

The companies plan to use this information in the development of a DNA-based test to identify individuals who are at elevated risk, thereby facilitating the implementation of preventive measures that can help minimize the risk of these individuals ever suffering a heart attack. deCODE receives a milestone payment from Roche for this discovery.

deCODE mapped the gene through a genome-wide linkage study involving a total of 2,000 patients and unaffected relatives from families across Iceland. The deCODE team then sequenced the gene and conducted an association analysis of patients and unrelated controls using more than 1,000 SNPs (single-nucleotide polymorphisms) within the locus. The two at-risk haplotypes, or forms of the gene, each delineated by only six SNPs, are both common and were found to confer significant risk of heart attack in the Icelandic population. These haplotypes confer risks equal to or greater than those conferred by other well-known risk factors, such as smoking, high blood pressure, high cholesterol or diabetes.

"This is a very important and exciting discovery, and underscores once again the advantages of deCODE's human genetics approach for discovering the major genetic risk factors for common diseases. By tracing how predisposition to myocardial infarction is inherited across the Icelandic population, we have pinpointed a major gene and a small number of genetic markers within that gene that define the increased risk," said Dr. Kari Stefansson, CEO of deCODE. "This is an important first step in empowering patients to minimize the health impact of a family history of heart attack. We are now working with our partners at Roche to validate and broaden our findings in diverse populations."