Background: Musculoskeletal function is often the limiting factor in quality of life in patients with mucopolysaccharidosis (MPS). The Pediatric Outcomes Data Collection Instrument (PODCI) is a validated tool to be used in children aged 2 to 18 years with chronic musculoskeletal disorders and is freely available to any investigator. The goal of this study is to establish normative data for patients with MPS.
Methods: Of our 25 patients with MPS, 16 had PODCI's performed at initial evaluation. This included 4 patients with MPS IH (Hurler), 7 patients with MPS II (Hunter), 4 patients with MPS IV (Morquio), and 1 patient with MPS VI (Maroteaux-Lamy). Differences in PODCI scores among children with MPS IH (Hurler), II (Hunter), and IV were estimated using a Kruskal-Wallis test.
Results: With the exception of upper extremity and physical functioning function in MPS IV, all domains for our MPS patients measured below average for typically developing children. We found a statistically significant difference among the groups in the upper extremity and physical function scale [H (2) = 8.16, P = 0.02]. The single MPS VI patient had the highest scores overall. MPS IV patients scored better than the MPS IH patients, and the MPS II patients scored lowest.
Conclusions: This study demonstrates the limited musculoskeletal function in patients with MPS and the differences among different MPS diagnoses.
Clinical relevance: The data establishes a basic understanding of musculoskeletal function in patients with MPS and should provide comparative data for future studies in which musculoskeletal function is measured as an objective outcome. It can also serve as a better objective measure for interventions, as previous models have only served as proxies to musculoskeletal function.