Integrated Management of an Adult Patient with Mucopolysaccharidosis type IVA: A Case Report with a Six-Year Follow-up.

ABSTRACT

Mucopolysaccharidosis type IVA (MPS-IVA) is a rare lysosomal storage disease caused by N-acetylglucosamine-6-sulfate-sulfatase enzyme deficiency. MPS-IVA patients show severe extra-skeletal and skeletal manifestations, featured by bone pain and deformities, frailty fractures and early onset osteoporosis. The enzyme replacement therapy (ERT) with elosulfase-α stabilizes the MPS-IVA extra-skeletal manifestations but does not significantly improve MPS-IVA skeletal manifestations. We administered an integrated therapy to an MPS-IVA 41-year-old male patient, composed of zoledronic acid, cholecalciferol and a normocalcemic (calcium intake ≥1 g/day), hyposodic (sodium intake ≤5 g/day), and normocaloric diet (bone-diet), other than ERT. During the six-year follow-up, the patient did not develop any adverse events, obtaining an improvement of bone mineral density and quality of life. Given our results, we propose this integrated treatment (i.e. ERT, zoledronic acid, cholecalciferol, and bone diet) in the management of MPS-IVA adult patients. LEARNING POINTS Mucopolysaccharidosis type IVA (MPS-IVA) is a genetic, rare, and degenerative spondylo-epiphyso-metaphyseal dysplasia characterized by extra-skeletal and skeletal manifestations. The latter impacts on MPS-IVA patient daily activities, and enzyme replacement therapy has a poor efficacy in improving skeletal involvement.The proposed integrated management with enzyme replacement therapy, zoledronic acid, cholecalciferol and bone diet improve both bone mineral density and the prognosis quoad valetudinem of our MPS-IVA patient.