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IEMbase 0241: IDUA-related Alpha-iduronidase deficiency

Scope

Field Value
IEMbase ID 241
Nosology 20.2.01.01
Gene IDUA
External IDs OMIM:607014; OMIM:607015; OMIM:607016; ORPHA:93473
Generated mapping MAPPED; Hurler_syndrome.yaml
Candidate DisMech targets Hurler_syndrome.yaml; umbrella context Mucopolysaccharidosis.yaml#MPS I (IDUA Mutations)
Review date 2026-07-07

IEMbase phenotype signal

IEMbase represents this as IDUA-related alpha-iduronidase deficiency, with alternate labels spanning mucopolysaccharidosis type 1H/Hurler syndrome, mucopolysaccharidosis type 1S/Scheie syndrome, and MPS I. The record is autosomal recessive and treatability is marked yes.

Treatment rows include hematopoietic stem cell transplantation, intrathecal iduronidase, and intravenous iduronidase. Biochemical rows include decreased alpha-iduronidase activity and increased urinary dermatan sulfate, heparan sulfate, and total glycosaminoglycans. Clinical and characteristic rows include cardiomyopathy, cervical myelopathy, coronary artery disease, delayed tooth eruption, diarrhea, genu valgum, glaucoma, hearing loss, intellectual disability, joint contractures, restrictive lung disease, seizures, swallowing difficulties, carpal tunnel syndrome, coarse facial features, corneal clouding, dysostosis multiplex, hepatosplenomegaly, hernias, hydrocephalus, kyphosis, macrocephaly, obstructive sleep apnea, retinal dystrophy, upper airway obstruction, and valvular thickening.

DisMech phenotype coverage

Hurler_syndrome.yaml is a high-concordance target for severe MPS I and also contains explicit related entries for Hurler-Scheie and Scheie syndrome. It covers biallelic IDUA disease, deficient alpha-L-iduronidase activity, dermatan/heparan sulfate storage, elevated GAGs, multisystem skeletal, cardiac, airway, ocular, neurologic, hepatic, and otologic disease, HSCT, laronidase/enzyme replacement, and investigational IDUA-directed therapy.

Mucopolysaccharidosis.yaml additionally has an umbrella subtype entry for MPS I (IDUA Mutations) that explicitly spans Hurler to attenuated Scheie phenotypes.

Concordance and completeness

Judgement: correct high-concordance mapping, with spectrum scope noted.

The generated mapping to Hurler_syndrome.yaml is valid because the local file covers the canonical IDUA/GAG-storage mechanism and includes severe and attenuated MPS I context. The main scope caveat is that the IEMbase label is an MPS I spectrum record rather than a Hurler-only record. Future mapping display should prefer the IDUA/MPS I spectrum when subtype-aware labels are available, while retaining Hurler_syndrome.yaml as the current strongest disease file.

Curation actions

  • Keep the current mapping to Hurler_syndrome.yaml.
  • Note the spectrum relationship to Hurler-Scheie and Scheie syndrome in any downstream curation queue.
  • Use IEMbase's dental, orthopedic, hematologic, vascular, and treatment rows as enrichment prompts if MPS I coverage is refreshed.