A 12-month-old girl is referred for genetic evaluation because of coarse facial features, an enlarged tongue, hepatosplenomegaly, joint stiffness, and delayed growth and development. She appeared normal at birth except for an umbilical hernia. Urine screening shows increased concentrations of dermatan sulfate and heparan sulfate. The child most likely has a disorder in the lysosomal metabolism of which of the following substances?

Question

Quizplus · Accepted Answer

The symptoms and urine findings are indicative of a mucopolysaccharidosis, which involves a disorder in the lysosomal metabolism of glycosaminoglycans. The child is most likely suffering from Hurler or Hunter syndrome. These disorders are characterized by the lysosomal accumulation of the glycosaminoglycans, dermatan sulfate, and heparan sulfate as a consequence of defects in the lysosomal hydrolases α-l-iduronidase or iduronate sulfatase, respectively.

A 12-Month-Old Girl Is Referred for Genetic Evaluation Because of Coarse