Iceland Creates DNA map of the "Entire Nation"

 Scientists in Iceland have produced an unprecedented snapshot of a nation's genetic makeup, discovering a host of previously unknown gene mutations that may play roles in ailments as diverse as Alzheimer's disease, heart disease and gallstones.



Daniel G MacArthur, a geneticist at Massachusetts General Hospital who was not involved in the research says, “They've now managed to get more genetic data on a much larger chunk of the population than in any other country in the world.“

In a series of papers published on Wednesday in the journal Nature Genetics, researchers at Decode, an Icelandic genetics firm owned by Amgen, described sequencing the genomes -the complete DNA -of 2,636 Icelanders, the largest collection ever analysed in a single human population. With this trove of genetic information, the scientists were able to accurately infer genomes of more than 1,00,000 other Icelanders, or almost a third of the entire country.

“From the technical point of view, these papers are a tour-de-force,“ said David Reich, a geneticist at Harvard Medical School who was not involved in the research.

While some diseases, like cystic fibrosis, are caused by a single genetic mutation, the most common ones are not. Instead, mutations to a number of different genes can each raise the risk of getting, say , heart disease or breast cancer. Discovering these mutations can shed light on them and point to potential treatments. But many of them are rare, making it necessary to search large groups of people to find them.
The wealth of data created in Iceland may enable scientists to begin doing that.

In their new study , the researchers at Decode present several such revealing mutations. For example, they found eight people in Iceland who shared a mutation on a gene called MYL4. Medical records showed that they also have early onset atrial fibrillation, a type of irregular heartbeat.

Gilian McVean, a geneticist at Oxford who was not involved in the study , said that discovering a rare association this way “is a bit of a holy grail“ for geneticists.

In recent years, geneticists have been searching for causes of disease not just by seeking out people who carry mutations, but also those who lack a working copy of a particular gene. Scientists call them human knockouts.

Sean E Harper, R&D head at biotechnology giant Amgen, said he expected many more insights from the DNA of Icelanders. “They can be guiding lights for us.“