Reykjavik, ICELAND, December 13, 2002 — deCODE genetics (Nasdaq/Nasdaq Europe:DCGN) announced today that a large association study carried out by its scientists and colleagues in Scotland has confirmed the significant link between the Neuregulin 1 gene and schizophrenia that deCODE has identified in Iceland. An article describing these findings will appear in the January 2003 edition of the American Journal of Human Genetics and is now accessible in online edition of the journal at www.ajhg.org.

“The direct replication of our findings in schizophrenia reported today offers yet more compelling evidence that the genes we are pulling out in Iceland are leading us to novel drug targets rooted in the basic biology of human disease. Working with collaborators in the United Kingdom, the United States and elsewhere, we are advancing rapidly in additional association studies in schizophrenia, stroke, and other of our most advanced gene and drug discovery programs,” said Dr. Kari Stefansson, CEO of deCODE genetics.

In July, deCODE scientists published the results of a major population study in Iceland linking a particular haplotype ― a piece of DNA code that is inherited as a unit ― of the Neuregulin 1 gene on chromosome 8 to an approximately twofold increased risk of schizophrenia. In the work announced today, the deCODE group and collaborators led by Professor David St Clair of the Aberdeen Royal Infirmary verified these findings through an analysis of DNA samples from more than 600 patients and a similar number of unaffected individuals from across central Scotland. The haplotype identified in Iceland, defined by five SNPs and two microsatellite markers, confers an approximately 1.8 times increased risk of schizophrenia in the Scottish cohort, very similar to that seen in Iceland.

deCODE has carried out substantial work in mice demonstrating that disruptions in the normal function of Neuregulin 1 promotes behaviors and disruptions in proper neurotransmission similar to those seen in schizophrenics. deCODE has identified lead series of compounds in its drug discovery work on targets within the Neuregulin 1 pathway. Later stage drug development work in schizophrenia will be conducted under the company’s therapeutics alliance with Roche.

About deCODE

deCODE is using population genetics to create a new paradigm for healthcare. With its uniquely comprehensive population data, deCODE is turning research on the genetic causes of common diseases into a growing range of products and services — in gene and drug discovery, DNA-based diagnostics, pharmacogenomics, bioinformatics, and clinical trials. deCODE’s pharmaceuticals group, based in Chicago, and deCODE’s biostructures group, based in Seattle, conduct downstream development work on targets derived from deCODE’s proprietary research in human genetics as well as contract service work for pharmaceutical and biotechnology companies. deCODE is delivering on the promise of the new genetics.SM Visit us on the web at www.decode.com.

Any statements contained in this presentation that relate to future plans, events or performance are forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. These forward-looking statements are subject to a number of risks and uncertainties that could cause actual results to differ materially from those described in the forward-looking statements. These risks and uncertainties include, among others, those relating to technology and product development, integration of acquired businesses, market acceptance, government regulation and regulatory approval processes, intellectual property rights and litigation, dependence on collaborative relationships, ability to obtain financing, competitive products, industry trends and other risks identified in deCODE’s filings with the Securities and Exchange Commission. deCODE undertakes no obligation to update or alter these forward-looking statements as a result of new information, future events or otherwise.