IEMbase 0592: NANS-related N-acetylneuraminic acid synthase deficiency
Scope
| Field | Value |
|---|---|
| IEMbase ID | 592 |
| Nosology | 18.4.03.02 |
| Gene | NANS |
| External IDs | OMIM:610442; ORPHA:168454 |
| Generated mapping | UNMAPPED; best candidate Spondyloepimetaphyseal_Dysplasia_Bieganski_Type.yaml |
| Candidate DisMech targets | None exact |
| Review date | 2026-07-07 |
IEMbase phenotype signal
IEMbase represents NANS-related N-acetylneuraminic acid synthase deficiency (CDG), with alternate labels NANS-CDG and spondyloepimetaphyseal dysplasia, Camera-Genevieve type. The record is autosomal recessive, classified under disorders of multiple glycosylation pathways, has unknown treatability, and has no treatment rows.
Biochemical rows include increased plasma and urinary N-acetyl-D-mannosamine. Clinical rows include developmental delay, seizures, microcephaly, short stature, facial dysmorphism, brachycephaly, broad nose, coarse face, flat ears, full lips, prominent forehead, sunken nasal bridge, synophrys, premature carpal ossification, small epiphyses, longitudinal metaphyseal striations, and skeletal dysplasia.
DisMech phenotype coverage
Spondyloepimetaphyseal_Dysplasia_Bieganski_Type.yaml is a false-positive
generated candidate. It models X-linked AIFM1-associated mitochondrial
spondyloepimetaphyseal dysplasia with neurodegeneration and hypomyelination.
It does not represent NANS, sialic-acid biosynthesis, N-acetylneuraminic acid
synthase deficiency, autosomal recessive inheritance, or N-acetyl-D-mannosamine
accumulation.
The local glycosylation entries provide broad CDG context, but no exact NANS-CDG / Camera-Genevieve target was identified.
Concordance and completeness
Judgement: true local gap; reject the Bieganski-type SEMD candidate.
The candidate shares skeletal-dysplasia language, but gene, inheritance, pathway, biomarker, and disease identity diverge. IEMbase should be curated as a NANS/sialic-acid biosynthesis CDG, not as AIFM1 mitochondrial skeletal-neurologic disease.
Curation actions
- Create or identify an exact NANS-CDG / Camera-Genevieve syndrome target before import.
- Reject
Spondyloepimetaphyseal_Dysplasia_Bieganski_Type.yamlas an exact mapping. - Preserve N-acetyl-D-mannosamine, skeletal maturation, metaphyseal/epiphyseal, facial, seizure, growth, and neurodevelopmental prompts.