Maroteaux-Lamy Syndrome (MPS VI)

Clinical Characteristics
Ocular Features: 

Corneal clouding is the cardinal ocular feature and is often visible by 5 years of age.  Several adult patients have had glaucoma with both open and closed angles.  The mechanism is unknown.  Optic nerve compression or secondary edema can cause a relatively sudden loss of vision.

Systemic Features: 

The lysosomal accumulation of glycosaminoglycans is responsible for the widespread signs and symptoms found in this disease.  Bone destruction in shoulders, hips and skull is often seen by the second decade of life and may become evident later in the knees and spine.  Early growth may be normal but eventually slows resulting in short stature.  Dysplasia of bones comprising these joints leads to stiffness and restricted movement.  The face is dysmorphic with coarse features.  Bone dysplasia and facial dysmorphism may be seen at birth.  Myelopathy and even tetraplegia can result from vertebral compression.  Intelligence is often normal although more severely affected individuals may have some cognitive defects.  Hepatosplenomegaly is common and compromised respiratory function can result in reduced physical stamina.  The tongue is usually enlarged.  Accumulation of dermatan sulfate in heart valves may produce insufficiency or restriction of outflow.

Genetics

MPS VI is a lysosomal storage disease inherited in an autosomal recessive pattern.  The responsible mutations lie in ARSB (5q11-q13), the gene that encodes the enzyme arylsulfatase B.  The phenotype results from defective dermatan sulfate breakdown with lysosomal accumulation.

Treatment
Treatment Options: 

Enzyme replacement therapy with galsulfase (Naglazyme®) is beneficial in alleviating some of the manifestations of this disease.  Orthopedic surgery for specific deformities may be necessary.  Visually significant corneal opacification may require corneal transplantation.

References
Article Title: 

Threshold effect of urinary glycosaminoglycans and the walk test as indicators of disease progression in a survey of subjects with Mucopolysaccharidosis VI (Maroteaux-Lamy syndrome)

Swiedler SJ, Beck M, Bajbouj M, Giugliani R, Schwartz I, Harmatz P, Wraith JE, Roberts J, Ketteridge D, Hopwood JJ, Guffon N, S?deg Miranda MC, Teles EL, Berger KI, Piscia-Nichols C. Threshold effect of urinary glycosaminoglycans and the walk test as indicators of disease progression in a survey of subjects with Mucopolysaccharidosis VI (Maroteaux-Lamy syndrome). Am J Med Genet A. 2005 Apr 15;134A(2):144-50.

PubMed ID: 
15690405

References

Swiedler SJ, Beck M, Bajbouj M, Giugliani R, Schwartz I, Harmatz P, Wraith JE, Roberts J, Ketteridge D, Hopwood JJ, Guffon N, S?deg Miranda MC, Teles EL, Berger KI, Piscia-Nichols C. Threshold effect of urinary glycosaminoglycans and the walk test as indicators of disease progression in a survey of subjects with Mucopolysaccharidosis VI (Maroteaux-Lamy syndrome). Am J Med Genet A. 2005 Apr 15;134A(2):144-50.

PubMedID: 15690405

Cantor LB, Disseler JA, Wilson FM 2nd. Glaucoma in the Maroteaux-Lamy syndrome. Am J Ophthalmol. 1989 Oct 15;108(4):426-30.

PubMedID: 2508477