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IEMbase 0264: Alpha-N-acetylgalactosaminidase deficiency, Schindler disease type III

Scope

Field Value
IEMbase ID 264
Nosology 20.3.05.03
Gene NAGA
External IDs OMIM:609241; ORPHA:79281
Generated mapping MAPPED; NAGA_Deficiency_Type_3.yaml
Candidate DisMech targets 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 III 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. Clinical rows include autism, cardiomyopathy, cataract, developmental delay, hepatomegaly, and seizures.

DisMech phenotype coverage

NAGA_Deficiency_Type_3.yaml is the correct local target. The local entry defines alpha-N-acetylgalactosaminidase deficiency type 3/Schindler disease type III as the intermediate NAGA deficiency phenotype between severe infantile type I and mild adult Kanzaki/type II disease. It covers biallelic NAGA variants, alpha-NAGA deficiency, glycoconjugate accumulation, glycopeptiduria and oligosacchariduria, seizures, behavioral difficulties, autism, psychomotor retardation, intellectual disability, congenital cataract, strabismus, hypertrophic cardiomyopathy, hepatomegaly, clinical heterogeneity, and supportive care.

Concordance and completeness

Judgement: correct mapping with high concordance.

IEMbase and DisMech agree on NAGA/type III identity, autosomal recessive inheritance, decreased alpha-N-acetylgalactosaminidase activity, autism or neurodevelopmental delay, seizures, cataract, cardiomyopathy, and hepatomegaly. DisMech is richer for spectrum placement, genotype/phenotype heterogeneity, and supportive care. The shared OMIM/ORPHA identifiers with the Schindler type I record appear to reflect source-level subtype grouping rather than equivalence between type I and type III disease entities.

Curation actions

  • Keep this record mapped to NAGA_Deficiency_Type_3.yaml.
  • No mapping correction is needed.
  • Use IEMbase's concise phenotype rows as confirmation prompts if the type 3 entry is reviewed further.