Abstract
INTRODUCTION: Mucopolysaccharidosis type IV A (MPS IVA) or Morquio A syndrome is an autosomal recessive lysosomal storage disease caused by GALNS gene mutations that lead to a deficiency of the N-acetylgalactosamine-6-sulfate sulfatase enzyme and the accumulation of two glycosaminoglycans in cell lysosomes, namely, chondroitin and keratan sulfate. OBJECTIVE: To present two female patients with Morquio A syndrome in their late adult years (over 50 years of age) with a classical phenotype, treated with enzyme replacement therapy; and to present a summary of the natural history and the characteristics of the disease, and the benefit of comprehensive management. MATERIALS AND METHODS: Descriptive clinical study before and after the treatment with enzyme replacement therapy as part of the comprehensive management of MPS IVA. RESULTS: Enzyme replacement therapy with elosulfase alfa was effective, with an adequate safety profile in these two patients, showing evidence of sustained improvement in terms of endurance and gait patterns. CONCLUSION: We present two cases of MPS IVA, with longer survival than reported previously in classical phenotypes associated with this disease condition. There is a paucity of reports of similar cases in the literature. We believe that the clinical heterogeneity of the disease manifesting with the classical phenotype, together with comprehensive management, have played a role in the survival of these two patients. Therapy with elosulfase alfa as part of comprehensive management has been crucial; we suspect a clinical response and infer a better quality of life and reduced burden for the caregiver, supporting its use in older patients.