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IEMbase 0251: HYAL1-related Hyaluronidase deficiency

Scope

Field Value
IEMbase ID 251
Nosology 20.2.11.01
Gene HYAL1
External IDs OMIM:601492; ORPHA:67041
Generated mapping MAPPED; Mucopolysaccharidosis_type_IX.yaml
Candidate DisMech targets Mucopolysaccharidosis_type_IX.yaml
Review date 2026-07-07

IEMbase phenotype signal

IEMbase represents this as HYAL1-related hyaluronidase deficiency, abbreviated MPS IX. The record is autosomal recessive and treatability is marked unknown, with no treatment rows in the cached JSON.

Biochemical rows include decreased hyaluronidase activity in plasma, increased urinary hyaluronic acid, and normal total urinary glycosaminoglycans. The clinical section has no additional rows in the cached JSON. Characteristic rows include cutaneous nodules, cutaneous swelling, degenerative hip dysplasia, joint contractures, and scoliosis.

DisMech phenotype coverage

Mucopolysaccharidosis_type_IX.yaml is the correct local target. The local entry covers HYAL1/hyaluronidase deficiency, hyaluronan accumulation, and the important point that total urinary GAGs may be normal. It frames the phenotype as a very rare, usually mild mucopolysaccharidosis with periarticular soft-tissue masses, painful joint swelling or nodules, mild short stature, scoliosis, hip dysplasia, joint-contracture-like musculoskeletal findings, and supportive management.

Concordance and completeness

Judgement: correct mapping with high concordance.

IEMbase and DisMech agree on HYAL1/MPS IX identity, hyaluronidase deficiency, hyaluronic acid/hyaluronan accumulation, normal total urinary GAGs, nodular or swelling soft-tissue disease, hip dysplasia, joint contractures, and scoliosis. The main wording difference is that IEMbase uses cutaneous nodules and swelling, whereas DisMech emphasizes periarticular soft-tissue masses and joint swelling.

Curation actions

  • Keep this record mapped to Mucopolysaccharidosis_type_IX.yaml.
  • No mapping correction is needed.
  • Consider whether the local phenotype wording should explicitly include cutaneous nodules/swelling as IEMbase uses those labels.