A case of two siblings with Morquio syndrome

Abstract

Morquio syndrome (Type IV mucopolysaccharidosis) is an autosomal recessive condition with a prevalence of 1:40000 to 1:200000.1 The deficiencies of N-acetyl-galactosamine-6-sulfatase and beta-galactosidase leads to accumulation of glycosaminoglycan resulting Morquio syndrome type A and B respectively. Here, we report a case of two siblings with Morquio syndrome. Parents brought two male siblings aged 5 years and 30 months due to abnormal physical appearance. They were born to non-consanguineous healthy parents who had uneventful antenatal periods. Parents were worried about short stature and abnormal chest shape. On examination, both of them had similar physical characteristics such as a coarse face, short stature, pectus carinatum, scoliosis, short neck, coxa vulga, and multiple bony deformities. They had normal basic biochemistry, haematological indices, and bone profil . Thoracolumbar spine and pelvis X rays showed platyspondyly with anterior beaking and flaring of iliac wings. Ophthalmology assessment of both siblings revealed amblyopia. Both siblings had elevated urine glycosaminoglycans. Qualitative urine analysis showed moderate excretion of chondroitin sulphate and mildly elevated Heparan sulphate, which favoured MPS type IV. Lysosomal enzyme assay performed on elder sibling showed a low level of beta-galactosidase-6-Sulphate-Sulphatase and normal level of beta-galactosidase, and the diagnosis was confi med as MPS type IV-A. Since no curative therapy was available yet, parents were explained about the disease condition, and follow-up was arranged with a multidisciplinary approach. Unfortunately, there is a significant amount of financial constraint in diagnosing and managing Morquio syndrome. Developing countries such as Sri Lanka cannot afford enzyme replacement therapy, and HSCT is not developed for children with inborn errors of metabolism. However, it is essential to have surveillance for anticipated complications of the condition with a multidisciplinary team approach until a cheaper disease-modifying agent is available.