Keratan and herparan sulfaturia: glucosamine-6-sulfate deficiency

The pattern of excretion of urinary acid mucopolysaccharides (AMPS) has been helpful to establish the diagnosis of mucopolysaccharidoses. The importance of urine analysis for AMPS and the specific enzyme assays is exemplified in a 3 1/2 year old Caucasian male with severe mental retardation, small stature, thoracolumbar kyphosis, and dysostosis multiplex. Urine analysis for AMPS revealed excessive quantities of keratan and heparan sulfate. This mucopolysacchariduria was not associated with hepatosplenomegaly or corneal clouding. Enzymic studies on cultured skin fibroblasts indicated deficiency of N-acetylglucosamine-6-sulfate sulfatase. This enzyme deficiency is different from that responsible for Morquio's syndrome, and early recognition is essential for proper counseling.