IEMbase 0533: ATP7A-related distal spinal muscular atrophy type 3
Scope
| Field | Value |
|---|---|
| IEMbase ID | 533 |
| Nosology | 22.1.03.01 |
| Gene | ATP7A |
| External IDs | OMIM:300489; ORPHA:404538 |
| Generated mapping | UNMAPPED; best candidate Menkes_Disease.yaml |
| Candidate DisMech targets | Menkes_Disease.yaml#ATP7A-related distal motor neuropathy |
| Review date | 2026-07-07 |
IEMbase phenotype signal
IEMbase represents ATP7A-related copper-transporting ATPase subunit alpha deficiency with the SMAX3 label. Alternate labels are X-linked distal spinal muscular atrophy and SMAX3. The record is X-linked, subtype is marked idiopathic, and no treatments are listed.
The IEMbase signal is narrow and motor-neuron predominant: normal serum copper, distal muscle weakness, weak or absent tendon reflexes, and possible optic nerve pallor. It does not present the severe infantile Menkes copper-deficiency phenotype.
DisMech phenotype coverage
The generated UNMAPPED status is a false negative if reviewed at the ATP7A
spectrum level. Menkes_Disease.yaml models ATP7A-related copper transport
disorders and explicitly includes ATP7A-related distal motor neuropathy /
X-linked distal spinal muscular atrophy type 3 as the mildest allelic variant.
The local subtype description distinguishes this from classic Menkes disease by
residual copper transport, adult-onset or milder distal motor weakness, and
little or no copper-deficiency biochemical pattern.
Concordance and completeness
Judgement: false negative; resolve to the ATP7A-related distal motor neuropathy
subtype within Menkes_Disease.yaml.
IEMbase and DisMech agree on ATP7A, X-linked inheritance, SMAX3/X-linked distal spinal muscular atrophy type 3 identity, and distal motor weakness. IEMbase adds explicit normal serum copper, weak/absent reflexes, and optic nerve pallor rows that should not be overwritten by classic Menkes assumptions.
Curation actions
- Map this record to
Menkes_Disease.yaml#ATP7A-related distal motor neuropathy. - Keep the note scoped to SMAX3 and do not treat it as classic infantile Menkes disease.
- Preserve normal serum copper, distal weakness, reflex, and optic nerve pallor prompts for subtype-specific review.