mpact of the Timing of Enzyme Replacement Therapy Initiation and Cognitive Impairment Status on Outcomes for Patients with Mucopolysaccharidosis II (MPS II) in the United States: A Retrospective Chart Review

Background: Mucopolysaccharidosis II (MPS II; Hunter syndrome; OMIM 309900) is a rare, X-linked, lysosomal storage disease caused by deficient iduronate-2-sulfatase activity. Accumulation of glycosaminoglycans results in multisystemic manifestations, which may include central nervous system involvement and cognitive impairment (CI). Patients with MPS experience high burden, leading to extensive healthcare resource utilization (HRU) reduced quality life. Objectives: This study aimed assess the impact timing enzyme replacement therapy (ERT) initiation CI status on clinical characteristics HRU patients II. Methods: A retrospective medical chart review 140 male who received diagnosis between 1997 2017 was performed at 19 US sites; data manifestations stratified age ERT or were analyzed for full population subgroup before 6 years. Results: In initiating 3 years age, there trend toward lower symptom burden compared initiated an older age. Evaluation developmental behavioral signs symptoms showed that communication delay (70.0% patients), (62.1%), problems (52.9%), toileting (50.0%) particularly common; earliest documented motor (median [range] first documentation: 4.2 [0.9-18.7] years) (4.4 [0.6-13.7] years). generally experienced greater higher than those without CI, most notable differences delays. Formal testing <30% cognitively impaired diagnosed Conclusions: Our findings reinforce previous recommendations be early maximally benefit II, especially younger old. Cognitively HRU. Patient care could improved assessments development treatments address decline.