Some 4,000 people will be invited to take part in the study, which will seek to better understand the causes of conditions such as diabetes, stroke, heart disease, cancer and others.
Researchers hope the findings will lead to new treatments for these conditions.
The unique genetic identity of those with Northern Isles ancestry offers a rare opportunity to give a detailed picture on how genes are implicated in health.
Those taking part in the University of Edinburgh study – called VIKING II – will complete an online questionnaire about their health and lifestyle.
They will also return by post a saliva sample kit, which will be analysed by researchers for factors including genetic sequencing.
The study is not limited to people who currently live in Orkney or Shetland. Those who are part of the global Northern Isles diaspora can also take part. There are significant numbers of diaspora from the Northern Isles to be living in Saskatchewan, Canada; Chicago, USA; and Dunedin, New Zealand, among many other parts of the world.
For those living in the UK who volunteer to be part of the study, they can choose to have information on limited genetic results returned to them through the NHS.
This information could be useful in terms of their future healthcare, including taking preventive actions to reduce the impact of health conditions. Lead researcher, Professor Jim Wilson, said: “People with Northern Isles ancestry tend to be descended from a relatively small number of founding families in the Viking age and through limited Scots immigration thereafter.
“Adding 4,000 more volunteers from these special populations will increase the scope and impact of our research into the genetics of health and disease. We hope in the long term, this will bring us a better understanding, which is the basis of new approaches to treat or prevent disease.”
People who would like to take part can register their interest by visiting the study website www.ed.ac.uk/viking.