Gross Motor Function Classification System in Patients with Mucopolysaccharidosis

Introduction Mucopolysaccharidosis (MPS) are a group of rare orthopedic disorders caused by heterogeneous genetic abnormalities in which lysosomal storage alteration lead to intracellular accumulation of glycosaminoglycans (GAGs) that injure and create dysfunction of varying degrees in multiple organs and systems, in a progressive and lethal way. The type of MPS can be classified according to the enzyme defect by which it is determined or according to its clinical manifestations and the progression of the disease The impairment of the musculoskeletal system or “dysostosis multiplex” is a common feature in all MPSs. It is characterized by osteoarticular deformities (kyphosis, scoliosis, knee valgus, equinovarus), joint stiffness with a loss in range of motion (ROM), and upper motor neuron impairment (myelopathy, hypertonia, spasticity). There is no specific motor function classification system for individuals with MPS. However, the progression of motor function impairment such as walking, sitting, and functional independence in day to day activities is directly related to the severity of the disorder...