IEMbase 0262: Alpha-N-acetylgalactosaminidase deficiency, Schindler disease type I
Scope
| Field | Value |
|---|---|
| IEMbase ID | 262 |
| Nosology | 20.3.05.01 |
| Gene | NAGA |
| External IDs | OMIM:609241; ORPHA:79281 |
| Generated mapping | MAPPED; NAGA_Deficiency_Type_3.yaml |
| Candidate DisMech targets | Schindler_Disease.yaml; NAGA_Deficiency_Type_3.yaml |
| Review date | 2026-07-07 |
IEMbase phenotype signal
IEMbase represents this as alpha-N-acetylgalactosaminidase deficiency with alternate labels Schindler disease type I and NAGA. The record is autosomal recessive and treatability is marked unknown, with no treatment rows in the cached JSON.
Biochemical rows include decreased alpha-N-acetylgalactosaminidase activity in fibroblasts and white blood cells, plus increased urinary N-acetylgalactosaminyl-oligosaccharides. Clinical rows include ataxia, neuroaxonal dystrophy, and exaggerated startle response.
DisMech phenotype coverage
Schindler_Disease.yaml is the correct local target. The local entry defines
Schindler disease as alpha-N-acetylgalactosaminidase deficiency type 1, the
severe infantile neuroaxonal-dystrophy form of NAGA deficiency. It covers
biallelic NAGA variants, loss of lysosomal alpha-N-acetylgalactosaminidase,
glycopeptide/glycoconjugate accumulation, urinary glycopeptide excretion,
developmental regression, hypotonia, spasticity, areflexia, blindness, hearing
impairment, CNS axonal spheroids, and supportive care.
NAGA_Deficiency_Type_3.yaml is not the right canonical target for this
IEMbase record because it represents Schindler disease type III, the
intermediate phenotype.
Concordance and completeness
Judgement: generated mapping is a false positive to type 3; resolve to
Schindler_Disease.yaml.
IEMbase and the local Schindler disease entry agree on NAGA/type I identity, alpha-N-acetylgalactosaminidase deficiency, urinary oligosaccharide or glycopeptide storage signal, autosomal recessive inheritance, and neuroaxonal dystrophy. IEMbase adds ataxia and exaggerated startle response as compact phenotype prompts. The generated type 3 target shares the enzyme defect but is the wrong severity/type entity.
Curation actions
- Remap this record to
Schindler_Disease.yaml. - Do not use
NAGA_Deficiency_Type_3.yamlas the canonical target for Schindler disease type I. - Use IEMbase's ataxia and exaggerated-startle rows as phenotype review prompts for the Schindler type I entry.