Pintos-Morell, GuillemBlasco-Alonso, JavierCouce, María LGutiérrez-Solana, Luís GGuillén-Navarro, EncarnaO'Callaghan, MarDel Toro, Mireia2025-01-072025-01-072018-04-052214-4269https://hdl.handle.net/10668/27103There is a growing interest in evaluating the effectiveness of enzyme replacement therapy (ERT) with elosulfase alfa in patients with mucopolysaccharidosis type IVA (MPS-IVA) under real-world conditions. We present the experience of seven pediatric MPS-IVA patients from the Spanish Morquio-A Early Access Program. Efficacy was evaluated based on the distance walked in the 6-min walking test (6-MWT) and the 3-min-stair-climb-test (3-MSCT) at baseline and after 8 months of ERT treatment. Additionally, urinary glycosaminoglycans were measured, and a molecular analysis of a GALNS mutation was performed. The health-related quality of life was evaluated using the EuroQoL (EQ)-5D-5 L. The distance walked according to the 6-MWT ranged from 0 to 325 m at baseline and increased to 12-300 m after 8 months with elosulfase alfa (the walked distance improved in all patients except one). An increase was observed for the two patients who had to use a wheelchair. Improvements were also observed for the 3-MSCT in four patients, whereas two patients showed no changes. Three patients showed an improvement in the EQ-VAS score, whereas the scores of three patients remained stable. Regarding urinary glycosaminoglycans measurements, an irregular response was observed. Our results showed overall improvement in endurance and functionality after 8 months of elosulfase alfa treatment in a heterogeneous subset of MPS IVA patients with severe clinical manifestations managed in a real-world setting.enAttribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/Elosulfase alfaLysosomal storage disorderMPS IVAMorquio AQuality of lifeUrinary GAGsresearch article30023300open access10.1016/j.ymgmr.2018.03.009PMC6047108https://doi.org/10.1016/j.ymgmr.2018.03.009https://pmc.ncbi.nlm.nih.gov/articles/PMC6047108/pdf