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IEMbase 0243: SGSH-related Heparan N-sulfatase deficiency

Scope

Field Value
IEMbase ID 243
Nosology 20.2.03.01
Gene SGSH
External IDs OMIM:252900; ORPHA:79269
Generated mapping MAPPED; Sanfilippo_syndrome.yaml#MPS IIIA
Candidate DisMech targets Sanfilippo_syndrome.yaml#MPS IIIA
Review date 2026-07-07

IEMbase phenotype signal

IEMbase represents this as SGSH-related heparan N-sulfatase deficiency, with alternate labels Sanfilippo A disease, mucopolysaccharidosis type 3A, and MPS IIIA. The record is autosomal recessive and treatability is marked yes, with no treatment rows in the cached JSON.

Biochemical rows include decreased heparan-N-sulfatase activity in white blood cells and increased urinary heparan sulfate and total glycosaminoglycans. Clinical rows include Alder-Reilly anomaly, diarrhea, dysostosis multiplex, hearing loss, liver dysfunction, macular involvement, and retinopathy. Characteristic rows include aggressive behavior, coarse facial features, hyperactivity, intellectual disability, neurologic regression, seizures, sleep disturbances, and swallowing difficulties.

DisMech phenotype coverage

Sanfilippo_syndrome.yaml#MPS IIIA is the correct local target. The local file has subtype coverage for SGSH-related Sanfilippo syndrome type A/sulfamidase deficiency, and the shared Sanfilippo entry covers autosomal recessive MPS III, failed lysosomal heparan sulfate catabolism, heparan sulfate accumulation, progressive neurodegeneration, intellectual disability, developmental regression, behavioral problems, hyperactivity, sleep disturbance, seizures, swallowing and feeding difficulty, hearing and visual impairment, mild systemic skeletal involvement, respiratory complications, and supportive/investigational therapy context.

Concordance and completeness

Judgement: correct subtype-level mapping with high concordance.

IEMbase and DisMech agree on SGSH/MPS IIIA identity, enzyme deficiency, heparan sulfate storage, total GAG elevation, neurobehavioral disease, seizures, sleep disturbance, swallowing difficulty, and systemic MPS features. IEMbase is more explicit for subtype-specific enzyme testing, Alder-Reilly anomaly, diarrhea, macular involvement, and retinopathy.

Curation actions

  • Keep this record mapped to Sanfilippo_syndrome.yaml#MPS IIIA.
  • No mapping correction is needed.
  • Use IEMbase's subtype-specific clinical rows as enrichment prompts if Sanfilippo phenotype detail is refreshed.