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IEMbase 0200: ATP7A-related occipital horn syndrome

Scope

Field Value
IEMbase ID 200
Nosology 22.1.02.02
Gene ATP7A
External IDs OMIM:304150; ORPHA:198
Generated mapping MAPPED; Menkes_Disease.yaml#Occipital horn syndrome
Candidate DisMech targets Menkes_Disease.yaml#Occipital horn syndrome
Review date 2026-07-07

IEMbase phenotype signal

IEMbase represents this as ATP7A-related copper-transporting ATPase subunit alpha deficiency, OHS subtype, with alternate labels occipital horn syndrome, X-linked cutis laxa, and OHS. Treatability is marked yes. The cached external ID uses OMIM:304150, which is the Menkes disease entry; the dedicated OHS phenotype MIM is a useful crosswalk follow-up but the source value is recorded as-is above.

The biochemical rows list low-to-normal serum ceruloplasmin and low-to-normal serum copper. Characteristic clinical rows are cutis laxa, diarrhea, pathognomonic occipital horn exostosis, and orthostatic hypotension. Additional rows include bladder diverticula and urinary infections. No treatment rows are listed in this cached record.

DisMech phenotype coverage

Menkes_Disease.yaml#Occipital horn syndrome is the correct target. The local entry treats OHS as an ATP7A allelic subtype of Menkes disease with residual copper transport, low copper and ceruloplasmin context, connective-tissue abnormalities, pathognomonic occipital exostoses, bladder diverticula, joint laxity, herniations/dental abnormalities in the subtype evidence, and milder or absent neurodegeneration compared with classical Menkes disease.

Concordance and completeness

Judgement: correct subtype mapping with high concordance.

IEMbase and DisMech agree on ATP7A/OHS identity, low copper/ceruloplasmin biochemistry, cutis laxa/connective-tissue disease, occipital horn exostoses, and bladder diverticula. IEMbase adds explicit diarrhea, orthostatic hypotension, and urinary infections as OHS-specific enrichment leads. DisMech is substantially richer for ATP7A mechanism, genotype-severity framing, the broader Menkes/OHS/distal motor neuropathy spectrum, copper histidinate context, and gene therapy context.

Curation actions

  • Keep this record mapped to Menkes_Disease.yaml#Occipital horn syndrome.
  • If the OHS subtype is enriched, consider adding diarrhea, orthostatic hypotension, urinary infections, and low-normal rather than frankly decreased copper/ceruloplasmin wording.
  • Keep this separate from classical Menkes disease when reviewing severity, neurodegeneration, and treatment responsiveness.