The epidemiology of Huntington disease in British Columbia

• Main Author: Fisher, Emily Rachel
• Language: English
• Published: University of British Columbia 2012
• Online Access: http://hdl.handle.net/2429/43319

Introduction: Global prevalence estimates for Huntington Disease (HD) vary widely, and those cited for Canada are outdated and not specific to British Columbia (BC). The most recent incidence calculation was performed in BC and includes diagnoses only up to the year 1999. Reports on the population at risk in Canada are based on theories and estimates that do not pertain to any particular population. Despite the presence of an extensive laboratory and clinical research hub in this province, a comprehensive epidemiological study of the prevalence, incidence and population at risk for HD has never been assessed. As such, the specific objectives of this study were to: 1) Calculate the minimum prevalence of HD in BC on April 1, 2012; 2) Calculate the incidence of HD in BC from January 1, 2001- December 31, 2011; and 3) Calculate the minimum population at risk for HD in BC on April 1, 2012. Methods: A comprehensive province-wide assessment of the HD patient population and the population at risk was conducted using multiple sources of ascertainment including: UBC HD clinic records, hospital and physician records, DNA diagnostic lab reports, the HD research lab at the Centre for Molecular Medicine and Therapeutics (CMMT), nursing homes, The Huntington Society of Canada and HD community members. Results: The minimum prevalence of HD in BC was estimated at 12.5 - 14.9/100,000 (95% CI: 11.5-16.0) (1/8,697 – 1/6,250), the incidence, 7.2 per million/year (95% CI: 6.5-7.9), and the minimum population at risk: 1/1,064 (95% CI: 1/1,941 - 1/2,107). Conclusions: The prevalence of HD is nearly twice as high as suggested by a previous Canadian report. This study comprised the most thorough HD patient ascertainment study since the advent of direct mutation testing and may set a precedent for future prevalence studies. Incidence has remained the same since 1999 and BC is only the fourth region in the world to provide a direct estimate of the population at risk for HD. === Medicine, Faculty of === Medical Genetics, Department of === Graduate