Ans. A (Arylsulfatase B). (Ref. Harrison, Medicine, 18th/ Chapter 361. Lysosomal Storage Diseases) Maroteaux-Lamy syndrome (MPS type VI) is due to deficiency of N-acetyl galactosamine (arylsulphatase B enzyme). Mucopolysaccharidoses (MPS) Disorder Enzyme Deficiency Stored Material Inheri- tance Neuro- logic Liver Spleen Enlarge- ment Skeletal Dysplasia Ophthal- mologic Hemato- logic Unique Features MPS I, Hurler -L-lduroni- dase Dermatan sulfate Heparan sulfate AR Mental retardation Mental retardation None + + + ++++ Corneal clouding Vacuola- ted lympho- cytes Coarse facies; cardiovas- cular involve- ment; joint stiffness MPS II, Hunter Iduronate sulfatase Dermatan sulfate Heparan sulfate X-linked Mental retardation, less in mild form + + + ++++ Retinal degene- ration, no corneal clouding Granula- ted lympho- cytes Coarse facies; cardiovas- cular involve- ment; joint stiffness; distinctive pebbly skin lesions MPS III, Sanfi- lippo A =Heparan -N-sulfa- tase. B=N-Acetyl -alpha-glu- cosamini- dase. C=Acetyl- CoA: Alpha -glucosa- minide N-acetyl- transferase. D=N-Acetyl glucosa- mine-6- sulfate sulfatase. Heparan sulfate AR Severe mental retarda- tion + + None Granula- ted lym- phocytes Mild coarse facies MPS IV A, Morquio N-Acetyl- galactose mine-6- sulfate sulfatase Keratan sulfate Chondroi- tin-6 sulfate AR None + ++++ Corneal clouding Granu- lated neutro- phils Distinctive skeletal deformity; odontoid hypopla- sia; aortic valve disease MPS IV B, Morquio Beta- Galacto- sidase AR None +- + + + + MPS VI, Marote- aux-Lamy Arylsulfa- tase B Dermatan sulfate AR None + + + + + + Corneal clouding Granula- ted neutron phils and lym- phocytes Coarse facies; valvular heart disease MPS VII Beta-Glu- curoni- dase Dermatan sulfate Heparan sulfate AR Mental retardation, absent in some adults + + + + + + Corneal clouding