Morquio syndrome or mucopolysaccharidosis (MPS) type IV is a rare autosomal recessive disease in which keratan sulfate builds up in cells. There are two variants, A and B, corresponding to deficiencies of two different enzymes. Type A is usually severe, although considerable clinical variability occurs due to the existence of attenuated phenotypes, which may escape diagnosis until adulthood. We illustrate this little known possibility by reporting a case of MPS IV A diagnosed in a 38-year-old woman. We review the clinical and radiological features of this disease, with which pediatricians are more familiar than other physicians. Our case provides an opportunity to emphasize the need for management by a rheumatologist in addition to the standard surgical treatment.