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Morquio A is a progressive disease. Early diagnosis is essential and enables optimal patient management through effective lifetime coordination of care across the multiple specialties needed to treat the disease.1,29,39


Clinical signs

Suspicion of Morquio A begins with clinical and/or radiographic findings. Patients typically appear normal at birth and develop symptoms between the first year of life through adolescence, depending on the rate of disease progression.4,29


  • Over 70% of Morquio A patients manifest with unusual skeletal features in the first few years of life; these features can be confirmed by clinical observation or skeletal radiograph.4
  • Patients with slowly progressing disease may be challenging to identify. Hip stiffness and pain are potential first signs of Morquio A in these patients.29,31

Laboratory Testing

Confirmation of Morquio A diagnosis requires biochemical testing and/or molecular analysis.29


  • Tests for urinary GAG carry high rates of false-negatives necessitating enzyme activity assay or molecular analyses for confirmation of Morquio A.29


  • Differentiation of similar MPS disorders, such as Morquio A and Morquio B, are critical in light of emerging therapeutic approaches.

Differential Diagnosis

Differential diagnosis of Morquio A from other Dysostosis multiplex MPS disorders and from additional skeletal dysplasias is essential.29

  • Biochemical and genetic findings are useful in distinguishing Morquio A from other MPS disorders.29
  • Enzyme analysis is recommended to rule out MPS IVB, which is characterized by deficient β-galactosidase activity.29

Radiographic findings as well as biochemical and genetic findings are useful in differentiating Morquio A from non-dysostosis multiplex skeletal dysplasias.29


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