IEMbase 0246: GNS-related N-Acetylglucosamine 6-sulfatase deficiency
Scope
| Field | Value |
|---|---|
| IEMbase ID | 246 |
| Nosology | 20.2.06.01 |
| Gene | GNS |
| External IDs | OMIM:252940; ORPHA:79272 |
| Generated mapping | MAPPED; Sanfilippo_syndrome.yaml#MPS IIID |
| Candidate DisMech targets | Sanfilippo_syndrome.yaml#MPS IIID |
| Review date | 2026-07-07 |
IEMbase phenotype signal
IEMbase represents this as GNS-related N-acetylglucosamine 6-sulfatase deficiency, with alternate labels Sanfilippo D disease, mucopolysaccharidosis type 3D, and MPS IIID. The record is autosomal recessive and treatability is marked yes, with no treatment rows in the cached JSON.
Biochemical rows include decreased N-acetylglucosamine-6-sulfatase activity in white blood cells, increased urinary heparan sulfate, and increased total glycosaminoglycans. Clinical rows include Alder-Reilly anomaly, coarse facial features, dysostosis multiplex, hearing loss, liver dysfunction, and neurologic regression. Characteristic rows include aggressive behavior, diarrhea, hyperactivity, intellectual disability, seizures, and swallowing difficulties.
DisMech phenotype coverage
Sanfilippo_syndrome.yaml#MPS IIID is the correct local target. The local file
has subtype coverage for GNS-related Sanfilippo syndrome type D/
N-acetylglucosamine-6-sulfatase deficiency and covers the shared Sanfilippo
mechanism of autosomal recessive heparan sulfate catabolic failure, lysosomal
heparan sulfate accumulation, progressive neurodegeneration, intellectual
disability, developmental regression, behavioral problems, hyperactivity,
seizures, swallowing and feeding difficulty, hearing and visual impairment, and
mild systemic MPS features.
Concordance and completeness
Judgement: correct subtype-level mapping with high concordance.
IEMbase and DisMech agree on GNS/MPS IIID identity, deficient N-acetylglucosamine-6-sulfatase activity, heparan sulfate storage, total GAG elevation, neurologic regression, intellectual disability, behavioral disease, seizures, swallowing difficulty, hearing involvement, and systemic MPS features. IEMbase provides a compact per-subtype checklist for enzyme testing and several systemic findings.
Curation actions
- Keep this record mapped to
Sanfilippo_syndrome.yaml#MPS IIID. - No mapping correction is needed.
- Use IEMbase's subtype-specific enzyme and phenotype rows as enrichment prompts for future Sanfilippo review.