Although Huntington’s disease is particularly common in northern Scotland, our data clearly shows that there is far more Huntington’s diagnosed now than the previous prevalence studies suggest, and more people with the HD gene are testing before the appearance of symptoms to access better care and research trials.
Since the identification of the Huntington’s gene in 1993 made testing for the condition possible, awareness has increased and a diagnosis can now be made in people unaware of their family history of the condition. Along with better care and hope of treatment trials, this has led to more people coming forward for testing.
We believe the high rates of HD diagnosis in Grampian and Highland are due to a combination of underlying genetic susceptibility in ancestral populations dating back to the rule of the Picts; increased awareness that diagnosis will lead to better care and support services; and the region having one of the oldest specialist Huntington’s research clinics in the world. Interestingly, there is also a higher incidence of of multiple sclerosis (MS) in the north of Scotland, though no equivalent genetic explanation for some of the cases.
We did note that the rates of Huntington’s also vary between the different health board regions in the north of Scotland, with more cases in Highland and fewer in Orkney and Shetland compared with Grampian. This local variation in rates could have major drug cost and service delivery implications for the NHS, especially if expensive, complexly administered therapies prove successful.
Although the condition is particularly common in northern Scotland, our data clearly shows that there is far more Huntington’s diagnosed now than the previous prevalence studies suggest, and more people with the HD gene are testing before the appearance of symptoms to access better care and research trials.