The incidence of Parkinsonism in patients with type 1 Gaucher disease: data from the ICGG Gaucher Registry.

PURPOSE: Investigate the incidence of Parkinsonism among patients with Gaucher disease type 1 (GD1) and describe demographics, genotypes, and Gaucher disease (GD)-related characteristics for affected and non-affected patients. STUDY TYPE: Cohort study with age- and gender-matched nested case-control analysis. Calculation of event incidence, standardized morbidity ratio, and event-free survival (Kaplan-Meier). DATA SOURCE: The International Collaborative Gaucher Group (ICGG) Gaucher Registry data as of June 2010. Study cohort: GD1 patients with any report of Parkinsonism. Pre-matching control group: All GD1 patients with no report of Parkinsonism. RESULTS: The matched study cohort comprised of 68 patients with reports of Parkinsonism and 649 patients without Parkinsonism. Demographic and clinical characteristics suggest a milder GD phenotype in patients with Parkinsonism compared to the control group. The most prevalent GD1 genotype was N370S/N370S (39% for controls; 46% for patients with Parkinsonism). Patients with Parkinsonism were diagnosed with GD1 at a mean age of 37 years compared to 31 years in control patients. The standardized morbidity ratio for the development of Parkinsonism among all GD1 patients indicated an approximately 6 to 17 fold increase over that of 2 reference populations. The mean age of reported Parkinsonism onset was 57 years compared to 60 years in the general population (Lees, Hardy, and Revesz, 2009 [1]). The probability that a patient with GD1 will develop Parkinsonism before age 70 years is 5 to 7% and 9 to 12% before age 80 years. CONCLUSIONS: The incidence of Parkinsonism among GD1 patients is significantly increased compared to two reference populations. GD1 patients with Parkinsonism have a later median age at GD diagnosis, later age at the start of treatment, and later age at death than patients with GD1 alone. The Gaucher-related clinical profile of GD1 patients with Parkinsonism is similar to or milder than the GD1 alone group. Therefore, severity of the common GD1 clinical manifestations does not appear to be predictive for the onset of Parkinsonism.