Mucopolysaccharidosis type VI (MPS VI), also known as Maroteaux-Lamy syndrome, polydystrophic dwarfism, and arysulfatase B (ASB) deficiency, is a lysosomal storage disorder with autosomal recessive inheritance characterized by progressive multisystem involved that causes many tissues and organs to enlarge and become inflamed. Skeletal deformities are common that progress and worsen in varying degrees thus affecting quality of life and life expectancy. Many studies have shown that allogeneic hematopoietic stem cell transplantation can reduce morbidity and enhance the survival and quality of life in such patients. We present a case of a 6-year-old girl diagnosed with MPS VI at the age of 3 years. Thereafter the patient developed various complications of the disease causing morbidity. She was then treated with combined umbilical cord blood (UCB) and bone marrow (BM) transplantation from complete human leukocyte antigen-matched (6/6) donor which was her younger sibling. The transplant was successful without any serious adverse effects. No additional treatments such as enzyme replacement therapy (ERT) were required. The transplantation of UCB along with BM can be considered as an effective treatment approach for this rare disease.
Plain language summary:

Case of MPS VI treated with stem cell transplantation: This article reports a case of a 6-year-old girl who was diagnosed with mucopolysaccharidosis type VI also known as MPS VI, an autosomal recessive disorder that caused her arysulfatase B (ASB) deficiency. This disorder affects growth velocity, gives coarse facial features, gives rise to skeletal deformities, frequent upper-airway infections, enlarged liver and spleen, hearing loss, and joint stiffness. However, very few studies have reported definitive ways to treat or cure MPS VI. To help her combat this disorder, combined umbilical cord blood and bone marrow transplantation was done. This transplant alleviated her symptoms, and the patient did not need any further treatment. Follow-up, 4 years after transplantation, shows normal enzyme level, no complications, and improved quality of life.