Electronic supplementary material
The online version of this article (doi:10.1186/1750-1172-9-32) contains supplementary material, which is available to authorized users.
Chris Hendriksz: Financial support has been received in person or by the institution from BioMarin in the following capacities: honoraria for lectures, chairman of advisory boards, consultant on projects, research trials and travel grants. Christine Lavery: Financial support has been received in person or by the Society for Mucopolysaccharide Diseases from BioMarin in the following capacities: participant on advisory board, patient access programme for clinical trials, travel grants and unrestricted educational grants. Mahmut Coker: The author declares that he has no competing interests. Sema Kalkan Ucar: The author declares that she has no competing interests. Mohit Jain: Receiving financial support/salary as employee of BioMarin. Lisa Bell: Receiving financial support/salary as employee of BioMarin. Christina Lampe: Received speaker’s and consultant honoraria, travel support and unrestricted grants from Shire, BioMarin and Genzyme.
CH: Contributed to questionnaire design and gave advice on results interpretation and analysis. CL: Contributed to project, questionnaire and focus group design, reached out to UK patients and gave advice on interpretation and analysis. MC & SKU: Contributed by gaining feedback from Turkish patients. MJ: Contributed as project lead across the whole project. LB: Contributed as project sponsor to project and questionnaire design. CL: Contributed to questionnaire design, led the ethics approval review, reached out to German patients and gave advice on interpretation and analysis. All authors reviewed the manuscript for important intellectual content and approved the final manuscript.
Morquio A syndrome (or mucopolysaccharidosis IVa) is an ultra-rare multi-organ disease, resulting in significantly impaired functional capacity, mobility and quality of life (QoL).
This patient-reported outcomes survey evaluated the global burden of Morquio A among adults (≥18 years, N = 27) and children (7-17 years, N = 36), including the impact on mobility, QoL, pain and fatigue. QoL was assessed using the general Health-Related Quality of Life (HRQoL) questionnaire (the EuroQol [EQ]-5D-5L). Pain and pain interference with daily activities were assessed using the Brief Pain Inventory Short Form (BPI-SF) in adults and the Adolescent Pediatric Pain Tool (APPT) in children. Fatigue was assessed by questioning the patients on the number of evenings in a week they felt extremely tired.
The clinical data showed a wide heterogeneity in clinical manifestations between patients, with the majority of patients showing differing levels of endurance, short stature, bone and joint abnormalities, abnormal gait and eye problems. Mobility was considerably impaired: 44.4% of children and 85.2% of adult patients were using a wheelchair. High wheelchair reliance significantly reduced QoL. This was mainly driven by reduced scores in the Mobility, Self-care, and Usual Activity domains. The HRQoL utility values were 0.846, 0.582 and 0.057 respectively in adults not using a wheelchair, using a wheelchair only when needed and always using a wheelchair; values were 0.534, 0.664 and –0.180 respectively in children. Employed adult patients had a better HRQoL than unemployed patients (HRQoL utility value 0.640 vs. 0.275, respectively).
64% of children and 74% of adult patients had joint pain; fatigue was reported by 69% of children and 63% of adults. Overall, increased mobility was associated with more severe and widespread pain and more fatigue.
The HRQoL of Morquio A patients is mainly driven by the ability to remain independently mobile without becoming wheelchair dependent. Their QoL reduces dramatically if they always have to use their wheelchair. Even a slightly better mobility (wheelchair use only when needed) greatly improves QoL. Maintenance of functional capacity and mobility paired with better pain management are likely to improve QoL.