You are examining a 5-year-old girl with severe psychomotor retardation. Physical examination shows distinct hepatosplenomegaly, corneal clouding, coarse facial features, and short stature. Suspecting a lysosomal storage disease you order a test for lysosomal enzyme activity in a skin biopsy. Results of the test shows deficiency in arylsulfatase B and accumulation of dermatan sulfates in the biopsy cells. Given these symptoms and lab studies, this child is most likely suffering from which of the following disorders?

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Quizplus · Accepted Answer

The symptoms and lab findings are consistent with Maroteaux-Lamy syndrome (Mucopolysaccharidosis type VI), which is characterized by a deficiency in arylsulfatase B leading to the accumulation of dermatan sulfate.  Maroteaux-Lamy syndrome is characterized by the lysosomal accumulation of dermatan sulfates as a consequence of deficiencies in the lysosomal hydrolase N-acetylgalactosamine 4-sulfatase (arylsulfatase B). Although mental development proceeds normally in Maroteaux-Lamy patients, the progression of physical and visual impairments ultimately impedes psychomotor abilities. The clinical features and severity in Maroteaux-Lamy patients is variable, but usually include short stature, hepatosplenomegaly, stiff joints, corneal clouding, cardiac abnormalities, facial dysmorphism, and dysotosis multiplex. Hepatosplenomegaly is always present in Maroteaux-Lamy patients after the age of 6. In patients with the most severe forms of the disease there is a shortened trunk, protuberant abdomen, and prominent lumbar lordosis

You Are Examining a 5-Year-Old Girl with Severe Psychomotor Retardation