For the first time in 35 years, the number of people in northern Scotland who have the Huntington’s gene has been counted, revealing that the region has one of the highest rates of the disease in the world.
The research, from the University of Aberdeen in partnership with NHS Grampian, found that confirmed that rates of Huntington’s disease in the region is 14.5 per 100,000 people – more than five times the estimated worldwide rate of 2.71 per 100,000 people.
The team used NHS family-based records, finding that there are more than 160 adults living in the area who have the Huntington’s gene but have not been tested, however, they suggest that the figure will be higher – as not everyone with Huntington’s disease symptoms seek diagnosis.
The University highlights that the analysis showed that, for every person who has been diagnosed with Huntington’s disease. there are another 2.2 relatives who have the gene., meaning that there are hundreds of people in Northern Scotland who could be considered for effective treatments for Huntington’s disease when these become available in the future.
Study lead, University of Aberdeen’s Professor Zosia Miedzybrodzka who is also NHS Clinical Lead for Huntington’s disease in North of Scotland, said: “It is crucial that we know this number, and that it is accurate, so that health boards can properly plan now for care, and for treatments when they become available in the future.”
Previous studies have looked at the number of people who tested positive for the Huntington’s disease gene, however, in this study, scientists used family tree clinical records to count how many people have a 50:50 chance of having inherited the neurodegenerative condition but have not been tested.
This meticulous approach has not been used in the UK since the Huntington’s disease gene was discovered in 1993.
Miedzybrodzka said: “Previous work looked at how many people in the area have been tested for Huntington’s disease, that is people diagnosed with Huntington’s disease signs and those with a gene alteration that will develop the condition in later life. However, no one has properly counted just how many people who haven’t been tested yet must have the gene.
“It is crucial that we know this number, and that it is accurate, so that health boards can properly plan now for care, and for treatments when they become available in the future.
“A 2022 Scottish government report underestimated Huntington’s disease rates and did not account for numbers of people at risk in a way that our clinic and lab data has.”
Genetic counsellor in NHS Grampian, Heather Cruickshank, said: “In 1989, when scientists previously studied this, testing was not possible, fewer people had a diagnosis of Huntington’s disease, and families were larger.
“But even now, despite high rates of testing, most people at risk of developing Huntington’s disease in Scotland have not had a test.
“There is a massive worldwide effort seeking treatments for Huntington’s disease.
“Going forward, services need to plan to treat these as yet uncounted people, as well as those currently diagnosed. Regional variations in rates will become more important, including genetic counselling and testing, management, and treatment delivery. Furthermore, better knowledge of the numbers of people who could benefit will encourage investment into drug discovery.
“Having a test remains a free choice for people from Huntington’s disease families and our research means that care can be planned for all those at risk, without people who don’t want a test having one.”
CEO of Scottish Huntington’s Association, Alistair Haw, said: “Earlier this term a Scottish Parliament motion calling for an expansion of specialist Huntington’s disease services in light of rising cases became the most supported motion in the history of devolution. This latest study further strengthens the case for immediate action to expand specialist services for families impacted by Huntington’s.
“Huntington’s disease is a hugely complex, widely misunderstood and extremely difficult to manage condition. Specialist services are not some ‘nice to have’ optional extra but an absolute necessity to prevent patients reaching crisis point and presenting to acute emergency statutory services. Specialist Huntington’s services need to be expanded urgently – a message further reinforced by this new and clear evidence which has major implications for health and social care providers throughout Scotland and beyond.”
