A 18-month-old boy is brought to the office due to developmental delay and failure to thrive. his mother states that he has recurrent ear infections since 6 months of age. Physical examination shows corneal clouding, hepatosplenomegaly, and restricted joint mobility. Further evaluation shows deficient phosphorylation of mannose residues on certain glycoproteins in the Golgi apparatus. In unaffected patients, these proteins are normally transported to which of the following cellular locations?

Question

A 18-month-old boy is brought to the office due to developmental delay and failure to thrive.  his mother states that he has recurrent ear infections since 6 months of age.  Physical examination shows corneal clouding, hepatosplenomegaly, and restricted joint mobility.  Further evaluation shows deficient phosphorylation of mannose residues on certain glycoproteins in the Golgi apparatus.  In unaffected patients, these proteins are normally transported to which of the following cellular locations?

Quizplus · Accepted Answer

Eductional Objective: Inclusion cell disease is a lysosomal storage disorder in which a defect in protein targeting prevents the phosphorylation of mannose residues required to tag acid hydrolases for transport to lysosomes.  Without these lysosomal proteins, cellular debris cannot be degraded and therefore accumulates within lysosomes, forming inclusion bodies characteristic of the disease.

A 18-Month-Old Boy Is Brought to the Office Due to Developmental