Mucopolysaccharidoses (MPS)

Mucopolysaccharidoses (MPS) are lysosomal storage disorders due to enzyme deficiencies impairing degradation of glycosaminoglycans (GAGs), also known as mucopolysaccharides.
GAGs are complex sugar molecules found in connective tissues, skin, cartilage, cornea, liver, spleen, and vascular tissues.
Examples: Dermatan sulfate, heparan sulfate, keratan sulfate, chondroitin sulfate, hyaluronic acid.
Most MPS disorders are autosomal recessive, except MPS II (Hunter syndrome), which is X-linked.

MPS Type	Gene	Enzyme Deficiency
MPS I	IDUA	Alpha-L-iduronidase
MPS II	IDS	Iduronate-2-sulfatase
MPS IIIA-D	SGSH, NAGLU, HGSNAT, GNS	Various (Heparan sulfate breakdown)
MPS IVA	GALNS	N-acetylgalactosamine-6-sulfatase
MPS IVB	GLB1	β-galactosidase
MPS VI	ARSB	Arylsulfatase B
MPS VII	GUSB	β-glucuronidase
MPS IX	HYAL1	Hyaluronidase