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 50â¯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.
ABSTRACT
Resumen: dentro de las displasias óseas hay cuadros clínicos que hacen parte de las denominadas condrodisplasias metafisarias, conocidas también como disostosis metafisarias, las cuales presentan mínimas diferencias entre sí, lo que las hace susceptibles de ser confundidas con otros cuadros clínicos como la acondroplasia y el raquitismo. En este artículo se presenta un caso clínico de condrodisplasiametafisaria tipo Schmid de un paciente de Popayán, Colombia, al igual que algunas consideracionessobre las principales características clínicas, radiológicas, de diagnóstico y tipo de herencia de esta enfermedad. El caso clínico corresponde a un paciente de género masculino de 23 meses de edad, en quien se inician estudios por la presencia de talla baja desproporcionada. Los resultados mostraron coxa vara, genu varo y extremidades cortas, con un fenotipo similar en la madre y el abuelo materno. Las radiografías evidencian la presencia de irregularidad con deshilachamiento de las metáfisis de huesos largos; además, ensanchamiento y esclerosis en las metáfisis proximales de ambos fémur. La meta final es ser confirmado por medio de pruebas genéticas. En conclusión, las condrodisplasias metafisarias, especialmente la tipo Schmid, son enfermedades caracterizadas por talla baja y hallazgos radiológicos especiales, dados principalmente por el compromiso metafisario a nivel de los huesos largos, que en conjunto con las características fenotípicas pueden conducir a la sospecha e identificación de este tipo de patología.
Abstract: between the dysplastic bone pathologies there are some medical conditions that belong to so-called metaphyseal chondrodysplasias, also known as metaphyseal dysostosis. These differ slightly from each other, making them capable of being confused with other medical conditions such as achondroplasia and rickets. This article presents a case of Schmid type metaphyseal chondrodysplasiafrom Popayan, Colombia, as well as some considerations about the main clinical characteristics, radiological, diagnosis, and type of inheritance of this disease. The clinical case corresponds to a male patient, 23 months old, who was studied by the presence of disproportionate short stature. Findings showed coxa vara, genu varus, and short limbs, with similar phenotype to the mother and maternal grandfather. The radiological images showed the presence of irregularity with ®fraying¼ of the metaphysis of long bones, in addition to widening and sclerosis in the proximal metaphysis of both femurs. The ultimate goal is to be confirmed by genetic testing. In conclusion, the metaphyseal chondrodysplasias, especially Schmid type, are diseases characterized by short stature and by special radiological findings, mainly given by the metaphyseal affectation of long bones, which together with the phenotypic characteristics may lead to the suspicion and identification of this disease.Keywords: Schmid type metaphyseal chondrodysplasia, osteochondrodysplasias, collagen type.
