Senior Director, Epidemiology Alexion, AstraZeneca Rare Disease Boston, United States
Background: Wilson disease (WD) is a rare, autosomal recessive disorder of copper metabolism. Limited population-based studies exist on the epidemiology of WD, including the prevalence of the disease in recent years.
Objectives: To utilize a real-world data source to describe the epidemiology of WD in France, including the prevalence of the disease, mortality, patient characteristics, and the proportion of patients with hepatic, neurologic, psychiatric, and ophthalmologic manifestations.
Methods: We conducted a retrospective, observational population-based study using the French national health insurance information system database (SNDS), which covers more than 66 million persons, and includes longitudinal data from 2009 to present. Prevalent WD cases were defined as patients with at least one hospital admission or specialized home care with a principal, related or associated diagnosis ICD-10 code E83.0 for copper metabolism disorder, or a long-term disease (Affection de longue durée (ALD)) associated with this code during the study period (2010-2019). Patients receiving copper replacement therapy (Menkes disease) were excluded. The yearly prevalence was calculated. In addition, the frequency of hepatic, neurologic, psychiatric and ophthalmic manifestations occurring at any time for prevalent patients was assessed through ICD-10 codes. Deaths were identified from the national death registry data.
Results: Overall, a total of 2,287 prevalent WD patients (52% male) were identified. Among these, 506 newly diagnosed WD patients were identified through an ALD; median age at time of diagnosis was 23 years (range < 5 to ≥60 years). Prevalence of WD increased from 14.9 per million in 2010 (the first full calendar year available), to 29.5 per million in 2019 (males: 30.8 per million; females: 26.9 per million), with a peak prevalence of 43.2 per million in the 18 to < 40 year age group. Among the prevalent cohort, hepatic manifestations were the most frequent (43.8%), followed by neurologic (32.7%), psychiatric (18.0%), and ophthalmic (1.6%). Approximately 9% of the prevalent patients had a discharge code for liver transplantation. Average annual mortality was 2.44% per year, with a mean age at death of 62 years.
Conclusions: Findings provide an updated understanding of the prevalence of WD, with results indicating a considerable level of morbidity in this population. Use of diagnostic codes associated with ALD and hospitalization may be considered to have high sensitivity for identifying diagnosed WD patients. Asymptomatic patients and those with less severe disease however were less likely to be captured. High capture of the French population overall and long-term follow-up further contribute to the strengths of this study.
