A genetic disorder resulting from a defect in a specific enzyme; one of a group of disorders called mucopolysaccharidoses (MPS). Characteristics of Morquio’s syndrome are retarded growth often resulting in dwarfism and abnormal muscular and skeletal development (chondrodysplasia) leading to kyphosis (excessive curvature of the spine), enlarged breastbone (sternum), fused or missing vertebrae, and knock-knees. The syndrome is often first diagnosed, when the child is learning to walk, by the unusual waddling gait.