Scientific Article

Skeletal Radiology

, Volume 43, Issue 3, pp 359-369

First online:

Open Access This content is freely available online to anyone, anywhere at any time.

Mucopolysaccharidosis IVA (Morquio A syndrome) and VI (Maroteaux–Lamy syndrome): under-recognized and challenging to diagnose

  • Ralph S. LachmanAffiliated withInternational Skeletal Dysplasia Registry, Cedars-Sinai Medical Center/University of California, Los AngelesInternational Skeletal Dysplasia Registry Email author 
  • , Barbara K. BurtonAffiliated withAnn and Robert H. Lurie Children’s Hospital of Chicago and Northwestern University Feinberg School of Medicine
  • , Lorne A. ClarkeAffiliated withChild and Family Research Institute, University of British Columbia
  • , Scott HoffingerAffiliated withStanford University School of Medicine
  • , Shiro IkegawaAffiliated withLaboratory for Bone and Joint Diseases, Centre for Integrative Medical Sciences, RIKEN
  • , Dong-Kyu JinAffiliated withSungkyunkwan University School of Medicine
  • , Hiroki KanoAffiliated withLaboratory for Bone and Joint Diseases, Centre for Integrative Medical Sciences, RIKEN
  • , Ok-Hwa KimAffiliated withAjou University Hospital
  • , Christina LampeAffiliated withUniversity Medical Center, University of Mainz
    • , Nancy J. MendelsohnAffiliated withChildren’s Hospitals and Clinics of Minnesota
    • , Renée ShediacAffiliated withBioMarin Pharmaceutical Inc.
    • , Pranoot TanpaiboonAffiliated withChildren’s National Medical Center
    • , Klane K. WhiteAffiliated withSeattle Children’s Hospital



Mucopolysaccharidosis IVA (MPS IVA, or Morquio A syndrome) and VI (MPS VI, or Maroteaux–Lamy syndrome) are autosomal recessive lysosomal storage disorders. Skeletal abnormalities are common initial presenting symptoms and, when recognized early, may facilitate timely diagnosis and intervention, leading to improved patient outcomes. Patients with slowly progressing disease and nonclassic phenotypes can be particularly challenging to diagnose. The objective was to describe the radiographic features of patients with a delayed diagnosis of MPS IVA or VI.

Materials and Methods

This was a retrospective study. The records of 5 MPS IVA and 3 MPS VI patients with delayed diagnosis were reviewed. Radiographs were evaluated by a radiologist with special expertise in skeletal dysplasias.


An important common theme in these cases was the appearance of multiple epiphyseal dysplasia (MED) with epiphyseal changes seemingly confined to the capital (proximal) femoral epiphyses. Very few patients had the skeletal features of classical dysostosis multiplex.


Radiologists should appreciate the wide phenotypic variability of MPS IVA and VI. The cases presented here illustrate the importance of considering MPS in the differential diagnosis of certain skeletal dysplasias/disorders, including MED, some forms of spondylo-epiphyseal dysplasia (SED), and bilateral Perthes-like disease. It is important to combine radiographic findings with clinical information to facilitate early testing and accurate diagnosis.


Mucopolysaccharidosis MPS Morquio Morquio A Maroteaux-Lamy MPS IVA MPS VI Dysostosis multiplex Multiple epiphyseal dysplasia MED Spondylo-epiphyseal dysplasia SED