1P36 Deletion Syndrome: Could there be a rare Celtic genetic link to medical condition?
We know that people living on the island of Ireland are more genetically prone to suffer from Cystic Fibrosis and have too much iron in their blood. But could there also be a Celtic gene link to another rare condition called 1P36? BBC NI's Dublin correspondent Shane Harrison reports.
It is late evening in the O'Nuallain family household in south Dublin.
Three-and-a-half-year-old Uisneach is playing with his mum, Miriam, and dad, Micheal.
Uisneach has the rare condition known as 1P36 Deletion Syndrome.
That means he is missing the first part, or tip, of one of his chromosomes.
He is a lovely, happy child but he has difficulty getting around, is small, has problems putting on weight, and cannot talk.
But his mother Miriam Murphy says her son is far from the worst affected.
"Uisneach is very fortunate in that he's definitely on the milder end of the spectrum. But he has suffered from a failure to thrive. He struggles to put on weight; he also has low muscle tone so he has difficulty crawling or walking. But we have been very lucky that he has avoided seizures and heart defects, some of the more serious things like that," she says.
Uisneach is one of only 12 registered cases in the Republic of Ireland.
And because the condition is so rare with no treatment for the underlying problem, his parents immediately sought out other families similarly affected via social media.
According to Micheal O Nuallain, Uisneach's father, it was then that they made an interesting discovery.
He said: "When we first made contact with other families in relation to 1P36 we were struck by how many seemed to have Irish connections; their surnames were often Irish. Then we attended a conference in Birmingham last August and that confirmed it to us, because so many there seemed to have Irish parents or grand-parents. To us, that suggested a pre-disposition in the Irish gene to the 1P36 condition."
It is known that the Irish are genetically more pre-disposed to suffer from Cystic Fibrosis, an inherited condition that critically affects the lungs and other organs.
And they are also more likely to have an iron overload in their blood, a condition known as Haemochromatosis.
But Andrew Green, the Professor of Medical Genetics at UCD, says there is a flaw in the supposition that there may be a Celtic gene linked to Uisneach's condition.
"I think that's a nice idea but not one that we can really support with science. For the vast majority of people who have this 1P36 Deletion it's something that starts as a new genetic event in them. It's not something they inherit from their parents or grand-parents. So, it's not something that we can say has been running through the Irish for generations. There's also evidence that it's there world-wide," he says.
Experts say the 1P36 deletion syndrome condition is relatively under-diagnosed and more needs to be done about informing the public and parents.
Parents, like Miriam and Micheal, urge those who think they might be affected to visit the 1P36 website.
They and other parents from Britain and Ireland will be holding a special conference on the issue next August in Belfast.