By combining the whole-genome sequences of thousands of people with nationwide family trees, it is possible to predict - "with substantial accuracy" - the genome of the entire nation.
The studies were written by a team of scientists from deCODE, the Reykjavik-based genetic analysts, and published in the journal Nature Genetics. The analysts used the latest DNA-reading technology to build this genetic portrait of Iceland.
Previously, explain the authors, scientists have used a system for switching off genes in mice for studying what genes do and how they affect health. Therefore, one of the published studies - titled "Identification of a large set of rare complete human knockouts" - set out to answer the question: "What if we could find people in whom genes had been switched off due to rare mutations?"
The researchers found that nearly 8% of the 104,000 participants had at least one gene that had been knocked out in this way. By examining the health of these individuals, the researchers believe that it will be possible to directly examine the effects of genes on human biology, which will open the doors to new drugs and diagnostics.
Another of the studies, "The Y-chromosome point mutation rate in humans," analyzed family tree data, looking at more than 500,000 years of male lineage to provide what the deCode team believes to be the most detailed and accurate ever estimate of the rate of mutation in the male sex chromosome.
They describe this rate "as a kind of evolutionary clock" for dating events in the evolution of humans. From this, they pinpoint the most recent common ancestor of all Y chromosomes in the world as having lived 239,000 years ago. This estimate breaks with previous studies - suggesting that the ancestor lived 100,000 years more recently and was much closer than previously thought to the mitrochondrial DNA that is passed along the maternal line.
'Much more than a molecular national selfie'
Kari Stefansson, founder and CEO of deCODE and lead author on the papers, says in a press statement that the combined results are "a demonstration of the unique power sequencing gives us for learning more about the history of our species and for contributing to new means of diagnosing, treating and preventing disease."
Stefansson also believes that the work shows how a small population can advance science worldwide with the generous participation of the majority of its citizens:
"In that sense this is very much more than a molecular national selfie. We're contributing to important tools for making more accurate diagnostics for rare diseases; finding new risk factors and potential drug targets for diseases like Alzheimer's; and even showing how the Y chromosome, a loner in the paired world of our genome, repairs itself as it passes from father to son. Other countries are now preparing to undertake their own large-scale sequencing projects, and I would tell them the rewards are great."
Speaking to the BBC, Stefansson suggested that by combining the whole-genome sequences of thousands of people with nationwide family trees, it is possible to predict - "with substantial accuracy" - the genome of the entire nation.
"We could, in Iceland, at the push of a button find all women who carry mutations in the BRCA2 gene," he told the news corporation. "This risk could basically be nullified by preventative mastectomies and ovariectomies. It would be criminal not to take advantage of it and I am convinced that my fellow countrymen will begin to use it pretty soon."