Smileband general news

The Irish are much more genetically diverse than previously believed and have Viking and Norman ancestry - just like the English, according to new research. A comprehensive DNA map of the people of the Emerald Isle has for the first time revealed lasting contributions from British, Scandinavian and French invasions. 

The findings are significant because they could be used in future studies to identify the genetics underlying various traits and diseases in specific regions.

An estimated 80 million people worldwide claim Irish descent - almost half of them Americans who regard it as their main ethnicity. 

It has long been assumed this means the blood in their veins is Celtic - but geneticists now say the truth is much more complicated. Their latest research has uncovered a previously hidden DNA landscape, shaped through geography and historical migrations. 

The findings, published in the journal PLOS Genetics, could also shed fresh light on genetic diseases - and lead to better treatments. 

In both the UK and Ireland, for example, prevalence of multiple sclerosis increases the further north you go. 

And compared with the rest of Europe, the Irish have higher rates of cystic fibrosis, celiac disease, and galactosemia, a serious metabolic disorder that prevents the breakdown of sugars in dairy, legumes and organ meats. 

In the 10,000 years since Stone Age cavemen first arrived, the Irish have established distinct cultural regions. 

But previous studies had identified no clear genetic groups within the population. 

Now researchers have found 23 distinct Irish genetic clusters, separated by geography by comparing mutations from almost 1,000 Irish genomes with over 6,000 from Britain and mainland Europe. 

These are most distinct in western Ireland, but less pronounced in the east, where historical migrations have erased the genetic variations. 

When the researchers took into account genetic contributions from people with British ancestry, a clear trend arose, showing this input dropping off in populations to the west. 

They also detected genes from Europe and calculated the timing of the historical migrations of the Norse-Vikings and the Anglo-Normans to Ireland, yielding dates consistent with historical records.