The prevalence and impact of scoliosis in Pompe disease: Lessons learned from the Pompe Registry
Pompe disease is a rare, autosomal recessive, progressively debilitating, and often fatal neuromuscular disorder. While scoliosis is common in many other neuromuscular disorders, there is little information on its prevalence and impact in Pompe disease. To further our understanding, we performed a cross-sectional analysis of data from the Pompe Registry, a multinational, long-term observational program that contains the largest collection of data in the world of patients with Pompe disease. In this analysis, patients were categorized by age during the natural history period (defined as the time when patients never received enzyme replacement therapy) and by age at onset of symptoms as infants (≤ 0 to < 2. years of age); children (≥ 2 to < 13. years of age); juveniles (≥ 13 to < 20. years of age); and adults (≥ 20. years of age). Scoliosis was defined by clinical assessment, X-ray of the spine, or both. Data on scoliosis were available in the majority of patients enrolled in the registry as of September 2010 (711/873, 81.4%). Scoliosis was present in a third of all patients with scoliosis data (235/711, 33%) in the Pompe Disease Registry. Scoliosis was found more frequently in patients with onset of Pompe symptoms as children (57.0%) and juveniles (52.9%) than in patients with onset of symptoms as adults (24.8%). Only 18.4% (38/206) of patients with onset of symptoms as infants were reported as having scoliosis. Scoliosis was reported in the majority (62.5%) of wheelchair users for all age groups. A larger percentage of patients with scoliosis required respiratory support than patients without scoliosis (44% vs 27.2%, respectively), and pulmonary function in those with scoliosis was consistently reduced in the 3 older age groups compared to those without scoliosis, with the largest differences demonstrated in juveniles. Patients with scoliosis had been diagnosed with Pompe disease for a mean of 1.2 (± 14.34) years before the first reporting of scoliosis. As with other registry analyses, data were collected from multiple sites in different countries and assessments of scoliosis therefore may not be based on consistent criteria. However, the observed occurrence of scoliosis across all age groups of patients with Pompe disease and its association with increased clinical morbidity, underscores the need for clinical assessment of scoliosis in all patients with Pompe disease.