Lysomal Storage Disorder

The Dwarf Pony

Mucopolysaccharidosis Type IVB

In mucopolysaccharidosis type IVA (MPS IVA, Morquio disease A, deficiency of the enzyme Acetylgalactosamine-6-Sulfatase) and type IVB (MPS IVB, Morquio disease B, deficiency of Beta-Galactosidase) predominantly the skeletal system is affected: Severe deformities of the spine, thorax and extremities result in disproportionate short stature, in severe cases the final height is about 120 cm. However, patients with a normal height have been described, too. Further characteristic features include joint laxity, instability oft the cranio-cervical junction, leading to paraplegia, corneal clouding and hearing problems. The intelligence is normal.

Mucopolysaccharidosis Type IVB | SphinCS - Clinical Science for LSD

Synonym: Morquio B syndrome
Etiology: Deficiency of beta-D-galactosidase
Gene: GLB1 Gene
Leading symptoms:

  • Skeletal abnormalities: dysostosis multiplex, dysproportioned dwarfism, cyphosis, pectus carinatum, genu valgum
  • Overly flexible joints
  • Respiratory problems
  • Hearing impairment


  • Measurement of the activity of beta-D-galactosidase
  • Molecular genetic analysis of GLB1 Gene

Only symptomatic

Current Studies

The "U.S. National Library of Medicine" provides a complete list of all international studies at The comparable EU website is less comprehensive:

Self-help groups

Gesellschaft für Mukopolysaccharidosen e.V.

At the moment we are not aware of any self-help groups.


At present we have no literature available.