Reykjavik, ICELAND and Basel, SWITZERLAND, May 22, 2001 — deCODE genetics (Nasdaq/Nasdaq Europe:DCGN) and Roche today announced two new accomplishments in their research alliance to characterize the genetic factors contributing to important common diseases. deCODE scientists have identified a gene causally involved in cerebrovascular disease, or stroke, and have mapped the chromosomal location of a gene linked to type 2 diabetes. Under the terms of their alliance, deCODE receives milestones payments from Roche for these discoveries.

deCODE isolated the stroke gene within the locus announced by the two companies last year. The gene is the first major genetic factor ever found for common forms of stroke. It was identified using a genome-wide linkage analysis of patients who suffered from stroke, using a broad but rigorous definition of the disease. This included ischemic stroke, in which blood clots block the extra- or intracranial vessels and which accounts for 80-90% of all stroke; hemorrhagic stroke, or rupture of intracranial vessels; and generally less serious clotting events known as transient ischemic attacks. In all, some 3000 Icelandic patients and family members participated in the study. Stroke is the third leading cause of death in the industrialized world, and Roche will incorporate drug targets identified through this gene into drug discovery programs.

Type 2, or adult-onset, diabetes accounts for around 90% of diabetes cases and is most prevalent among people over the age of 40 and the severely obese. It is characterized by the body’s inability to adequately regulate blood sugar levels through proper insulin secretion and response. Type 2 diabetes is also associated with high blood pressure and narrowing of the arteries. deCODE was able to narrow the location of the gene to a small chromosomal region, utilizing the genotypes of 2700 volunteer patients and relatives grouped into 200 families from across Iceland. Roche intends to use this information to develop second generation diagnostic tools and new treatments that will help patients maintain normal insulin responsiveness.

Kari Stefansson, CEO of deCODE, said, “We are proud to have identified the first gene involved in the most common forms of stroke, and we are excited that Roche will be taking this result straight into drug discovery. I am also confident that, as in

our stroke research, we will soon be able to find a gene within the type 2 diabetes locus we have identified and use this gene to identify powerful new drug targets.”

“Once again, we are encouraged by the pace and quality of deCODE’s discoveries,” commented Jonathan Knowles, Roche’s Global Head of Research. “We will be moving promptly to use this important progress in our understanding of the molecular pathology of stroke and late-onset diabetes to develop new products for better diagnosis, treatment and prevention of these diseases, thus translating this new knowledge as quickly as possible into benefits for patients and their families.”

deCODE genetics (www.decode.com), based in Reykjavik, Iceland, is conducting research into the inherited causes of common diseases. Through its population-based approach and three main business units providing disease-gene and drug target identification, database services and informatics tools, deCODE is turning raw genomics data into products and services for the healthcare industry.

Headquartered in Basel, Switzerland, Roche is one of the world’s leading research-oriented healthcare groups in the fields of pharmaceuticals, diagnostics and vitamins. Roche’s innovative products and services address needs for the prevention, diagnosis and treatment of disease, thus enhancing people’s well-being and quality of life. Roche has approximately 65,000 employees and sells its products in over 170 countries. Research at Roche is focusing on diseases with high unmet medical need in the areas of the central nervous system, genitourinary diseases, metabolic diseases, inflammation and bone diseases, oncology and vascular diseases as well as viral diseases.

Any statements contained in this press release that relate to future plans, events or performance are forward-looking statements that involve risks and uncertainties including, but not limited to, those relating to technology and product development, market acceptance, government regulation and regulatory approval processes, intellectual property rights and litigation, dependence on strategic partners, ability to obtain financing, competitive products and other risks identified in deCODE’s filings with the Securities and Exchange Commission. Actual results, events or performance may differ materially. deCODE undertakes no obligation to publicly release any revisions to these forward-looking statements resulting from events or circumstances after the date hereof.