Kári Stefánsson

Kári Stefánsson (or Kari Stefansson; born 6 April 1949) is an Icelandic neurologist and founder and CEO of Reykjavik-based biopharmaceutical company deCODE genetics.

In Iceland he has pioneered the use of population-scale genetics to understand variation in the sequence of the human genome.

His work has focused on how genomic diversity is generated and on the discovery of sequence variants impacting susceptibility to common diseases.

This population approach has served as a model for national genome projects around the world and contributed to the realization of several aspects of precision medicine.

Kari Stefansson was born in 1949 in Reykjavik, Iceland.

He was the second youngest of the five children of Sólveig Halldórsdóttir and Stefán Jónsson, a radio personality, writer and democratic socialist member of parliament.

He completed his secondary education at Reykjavik Junior College and received his M.D. in 1976 and his Dr. med. in 1986 from the University of Iceland.

He was married to Valgerður Ólafsdóttir from 1970 until her death on 11 November 2021.

There he completed residencies in neurology and neuropathology, and in 1983 joined the faculty.

However, in the mid-1990s the tools for reading the sequence of the genome were primitive.

Data was scarce and expensive to generate, and a major early focus of the Human Genome Project was to develop better methods.

In the meantime, one solution was to use genetics – how the genome is mixed and passed from one generation to the next – as a means of deriving more information from the available data.

Siblings share half their genomes; but cousins one eighth, second cousins one thirty-second, etc. Studying patients linked by extended genealogies should therefore make it possible to more efficiently find the inherited component of any phenotype or trait, even using low-resolution markers.

An important question was whether and where such extended genealogies might be found.

It was not one that occurred to many leading geneticists to ask with regard to common diseases.

As an Icelander, Stefansson knew the country's passion for genealogy first hand and had grown up with and trained in its national health system.

In 1993 he was appointed professor of neurology, neuropathology and neuroscience at Harvard University and division chief of neuropathology at Boston's Beth Israel Hospital.

While in Boston, he and his colleague Jeffrey Gulcher decided to return to Iceland to perform genetic studies to determine multiple sclerosis risk.

In 1995, he and his colleague and former graduate student, Jeffrey Gulcher, decided to go to Iceland to study multiple sclerosis.

Working with doctors in the national health system they identified hundreds of patients and relatives who gave them blood samples to begin their research.

As Icelanders they were almost by definition related, and due to the national pastime of genealogy those relationships could be established.

When Stefansson and Gulcher returned to Boston, their grant proposal was turned down by the NIH, which had little experience of funding work using distantly related patients.

But Stefansson saw potential in Iceland for using the same approach to find the genetic component of virtually any common disease.

This was beyond the scope of an academic laboratory, and he made contact with venture capital firms to find out if such an enterprise could be funded as a private company.

In the summer of 1996 he raised $12 million from several American venture capital funds to found deCODE genetics.

Stefansson resigned both positions in 1997 after founding deCODE and moving back to Reykjavik.

Since 2010, he has held a professorship in medicine at the University of Iceland.

He is a board-certified neurologist and neuropathologist in both Iceland and the US.

Stefansson's academic work was focused on neurodegenerative disease.

The protein biology approach to this research involved trying to map complex processes using limited samples, mainly of brain tissue from deceased patients.

Although publishing steadily, Stefansson was frustrated by the pace of progress and often by not knowing whether the proteins he was characterizing were involved in causing disease or the product of the disease process.

He and his colleagues came to question even the accepted definition of multiple sclerosis (MS) as an autoimmune disease.

When he was recruited from Chicago to Harvard, Stefansson began to think that the genome might provide a better starting point than biology.

Genes encode proteins, so identifying the genes and specific genetic variations that patients tended to share more often than healthy individuals should provide a foothold in the pathogenesis of disease.

In doing so they might point to biologically relevant targets for new drugs and predictive diagnostics.

In June 2012, his daughter, Sólveig "Sóla" Káradóttir, married Dhani Harrison, son of the late George Harrison and his wife, Olivia Harrison.

Stefansson says that he owes much to his brother, who suffers from schizophrenia.

He initially thought of becoming a writer, and attests to being a voracious reader.

His favorite author is Isaac Bashevis Singer.

Following his internship at the National Hospital of Iceland, he went to the University of Chicago to work under Barry Arnason (coincidentally a Canadian of Icelandic descent).