Table 1 Overview of the mucopolysaccharidoses (MPS)
From: Assessment of musculoskeletal abnormalities in children with mucopolysaccharidoses using pGALS
MPS Type | Main clinical features | Enzyme deficient | Substrate accumulated |
|---|---|---|---|
Skeletal disease, soft tissue storage and a range of central nervous system disease | |||
I-H Hurler | Developmental delay, coarse facial features, dysostosis multiplex, hepatosplenomegaly, death by age 10 years | Alpha-L-iduronidase | Heparan sulfate |
I-HS Hurler-Scheie | Micrognathia, toe walking, moderate coarse facies, possible normal intelligence, death by 20s (phenotype intermediate between I-H and I-HS) | Dermatan sulfate | |
I-S Scheie | Aortic valve disease, joint disease, corneal clouding, normal facies, survive into adulthood | ||
II Hunter | Severe: Disease course similar to MPS I-H, but clear corneas, aggressive behaviour and developmental delay | Iduronate sulfatase | Heparan sulfate |
Mild: Normal or near-normal intelligence, less pronounced physical features | Dermatan sulfate | ||
MPS VII Sly | Variable intermediate presentation similar to MPS I, from fetal hydrops to mild dysmorphism; dense inclusions in granulocytes | Beta-glucuronidase | Heparan sulfate |
Dermatan sulfate | |||
MPS VI Maroteaux-Lamy | Similar to MPS I without CNS disease, pachymeningitis cervicalis, death in teens and 20s; Hurler phenotype with marked corneal clouding; mild, moderate and severe expression in different families | N-acetylgalactosamine-4-sulfatase (arylsulfatase B) | Dermatan sulfate |
Skeletal, cartilage and ligament disease primarily | |||
MPS IVA Morquio A | Skeletal disease (bone dysplasia) with short stature, ligamentous laxity, corneal opacities, final height <125 cm | N-acetylgalactosamine-6-sulfatase | Keratan sulfate |
MPS IVB Morquio B | Same as IV-A but milder; adult height >120 cm | Beta-galactosidase | |
MPS IX Natowicz syndrome | Periarticular masses, nodular synovium, popliteal cyst, large joint effusion | Hyaluronidase 1 | Hyaluronan |
MPS IIIA Sanfilippo A | Behavioural problems, sleeping disorder, aggression, progressive dementia, mild dysmorphism, coarse hair, clear corneas, survival to adulthood possible | Sulfamidase | Heparan sulfate |
MPS IIIB Sanfilippo B | Alpha-N-acteylglucosaminidase | ||
MPS IIIC Sanfilippo C | GAC-acteylase | ||
MPS IIID Sanfilippo D | N-acetylglucosamine-6-sulfatase | ||