Study finds people in remote areas more likely to develop certain diseases
The University of Edinburgh's study considered a number of factors
People from isolated parts of the UK could have variations in their genetic code that increase their chance of developing certain diseases, research suggests.
The study found the most genetically distinct populations are in Shetland and Orkney, where some disease-causing variants - changes in the DNA sequence that make up a gene - are more than 100 times more common when compared to other parts of the UK.
Scientists also found populations in north and south Wales, south-east Scotland, Ireland and some parts of England carry genetic variants that are up to 73 times more common than in the wider population.
The University of Edinburgh-led study identified six disease-causing variants among those from Shetland, including one linked to Batten disease - a life-limiting neurodegenerative condition in children.
An estimated one in 41 Shetlanders are carriers of the condition, which can involves vision problems, seizures, poor circulation, decreased muscle mass and curvature of the spine.
It normally onsets between the ages of five and 10 and is terminal.
The team says the findings highlight the link between ancestry and health in remote communities, as populations in these regions are less genetically diverse when compared to cities as fewer people move in and out of the area.
As a result, rare genetic variants that can cause certain diseases can become more common and be passed down through generations.
These genetic variants, the research team said, may only be visible if a person has two copies of it in their DNA, as those with just one copy may be unaware they are carriers.
The research analysed anonymous genetic information from more than 44,000 people across 20 regions of the UK, based on data from the UK BioBank database and Viking Genes studies.
Due to a lack of available information, they were unable to include every part of the UK.
Professor Jim Wilson, study lead from the University of Edinburgh'sUsher Institute, said: "The enrichment of otherwise rare disease-causing genetic variants in regional populations in Britain, particularly in Shetland, but also Orkney and Wales, should inform genomic medicine strategies.
"Targeted screening for genetic disorders is common in Jewish populations, including in England.
"Our results show that genetic screening is also warranted in other UK communities, particularly Shetland."
The research team found nine disease-causing variants at much higher frequencies in Wales, including one causing an inherited form of kidney stones disorder, which is 44 times more common in south Wales than in the general population.
The 10 English regions included in the study were not as genetically distinct, the researchers found.
The team said this could reflect the lack of geographic or cultural barriers between the regions, such as sea channels, mountains or language differences.
Despite this, a number of rare variants were found to be more prevalent in areas including Lancashire, Staffordshire and Nottinghamshire.
People from Lancashire were found to be 73 times more likely than the general UK population to carry a variant linked to Zellweger syndrome, a disease affecting the brain, liver and kidneys which is fatal in the first year of life.
Researchers said the findings highlight the need for further research into rare genetic variants in regions across the UK.
Any future genetic screening programmes, designed to identify those at risk of disease, should be tailored to include common variants in the region, they added.
The study, funded by the Medical Research Council Human Genetics Unit, is published in the journal Nature Communications.