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Mucopolysaccharidosis type IX: causes, symptoms, diagnosis, treatment
Medical expert of the article
Last reviewed: 07.07.2025
ICD-10 code
- E76 Disorders of glycosaminoglycan metabolism.
- E76.2 Other mucopolysaccharidoses.
Epidemiology
Mucopolysaccharidosis type IX is an extremely rare form of mucopolysaccharidosis. To date, there is a clinical description of one patient, a 14-year-old girl.
Causes of mucopolysaccharidosis type IX
Mucopolysaccharidosis type IX is caused by mutations in the HYAL1 gene, mapped to chromosome 3p.21.2. The gene encodes the enzyme hyaluronidase.
Symptoms of mucopolysaccharidosis type IX
The main clinical manifestations of the disease are symmetrical nodular deposits in the parotid regions, mild dysmorphic features, growth retardation and preserved intelligence; joint stiffness is absent. Radiography revealed multiple ulcerations of the acetabulum.
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