Genetic map of Ireland unlocks secrets about ancestors

The information could be used to support future efforts to identify genetic predictors of human disease

The first genetic map of the people of Ireland has been produced by scientists and genealogical researchers here.

The study has found that prior to the mass movement of people in recent decades, there were at least 10 distinct genetic clusters found in specific regions across Ireland.

It also revealed that seven of those clusters discovered so far are of 'Gaelic' Irish ancestry and match the borders of either Irish provinces or historical kingdoms.

The other three are of shared Irish-British ancestry, and are mostly found in the north of Ireland and probably reflect the Ulster Plantations.

The research was carried out by scientists at the Royal College of Surgeons in Ireland working with the Genealogical Society of Ireland.

Those behind the study say the information could in time be used to support future efforts to identify genetic predictors of human disease.

"Having a genetic map of the Irish population will be invaluable in future studies of the genetic component of some common diseases in the Irish population, especially those diseases which show a difference in prevalence rates across the Island of Ireland," said Sean Ennis from UCD ACoRD and Genomics Medicine Ireland who co-authored the paper.

The Irish DNA Atlas also found that two of the 'Gaelic' clusters together align with the boundaries of the province of Munster.

It also discovered that they are individually associated with the boundaries of the kingdoms of Dál Cais and the Eóganacht.

The Celtic and Viking influence was also evident in the findings with relatively high levels of North-West French-like and evidence of West Norwegian-like ancestry identified.

Ireland's tradition of migration was also apparent with evidence of continual, low level migration between the north of Ireland and the south and west of Scotland.

The study, designed by population geneticists and genealogists involved the collection of DNA samples from 196 people here spanning four generations of ancestry linked to specific areas across the island of Ireland.

That genetic code was then analysed and compared with thousands of further samples from Britain and Europe.

"Historians and students of medieval Ireland have now a wonderful resource on the movements and interrelationships of our ancestor groups through their DNA," said Michael Merrigan from GSI who was a co-author on the paper.

"This opens up many new and very exciting research opportunities for many disciplines, especially, those researching the Irish medieval genealogies and the history of Irish clans/septs."

The study is ongoing and those behind it are looking for people who have ancestry from a specific part of Ireland to participate by contacting Séamus O'Reilly from the Genealogical Association of Ireland via irish.dna@familyhistory.ie.

Details of the findings were published in the journal Scientific Reports.