Northern Scotland has one of the highest rates of Huntington’s disease in the world, with diagnoses increasing nearly 50% in the past three decades, according to a study.
Researchers at Aberdeen University found the number of people within the NHS Grampian region who have the faulty gene that causes the illness as well as noticeable symptoms has jumped 46% since 1984.
Across the region, 14.6 people per 100,000 have a diagnosis as well as noticeable symptoms – more than five times the estimated worldwide prevalence of 2.71 per 100,000.
The figure 36 years ago for the NHS Grampian area was 9.94 per 100,000.
A university spokesperson said: “The rates of the condition also vary between the different health board regions in the north of Scotland, with more cases in Highland and less in the Northern Isles compared with Grampian.”
Huntington’s is a complex hereditary neurological condition which can cause sufferers to lose the ability to walk, talk, eat and drink by degrading motor and cognitive facilities. There is currently no cure.
Symptoms usually begin between the age of 30 and 50, and it takes between 10 and 25 years typically from a person developing the illness until they die, according to the study, published in the Journal of Neurology.
Since the Huntington’s gene was identified in 1993, more people have been tested to see if they carry it, study authors said. Each child of a person who has Huntington’s is at a 50% risk of inheriting it.
Researchers believe the high rates of diagnosis in both Grampian and Highland are due to “the combination of underlying genetic susceptibility in the ancestral populations, increased awareness of the benefits of diagnosis (better care and support services) in affected families and medical practitioners, and the region having one of the oldest specialist Huntington’s Disease research clinics in the world”.
Professor Zosia Miedzybrodzka, from the University of Aberdeen, is the lead study author and the consultant in charge of NHS Grampian’s north of Scotland Huntington’s clinics.
She said: “In the north of Scotland, an area known to have high levels of Huntington’s disease, there has been a 46% increase over the last 30 years.
“The emergence of the genetic test which people, with or without symptoms, come forward to take is likely to have contributed to the increase in those diagnosed with Huntington’s.
“Even in a country the size of Scotland, there is quite a variation in prevalence between different health board regions.
“This difference could have major drug cost and service delivery implications, especially if expensive, complexly-administered therapies prove successful.
“Health services should gather accurate population-based data on a regional basis to help inform service planning.”
Alistair Haw, chief executive of the Scottish Huntington’s Association, said: “Huntington’s disease is a hugely complex, widely misunderstood and extremely difficult to manage condition – meaning specialist services are not some nice-to-have optional extra, but an absolute necessity.”