Skip to content

IEMbase 0790: ADA2-related adenosine deaminase 2 deficiency

Scope

Field Value
IEMbase ID 790
Nosology 16.2.08.01
Nosology code IEM0014
Gene ADA2
External IDs OMIM:607575; ORPHA:404553
Generated mapping UNMAPPED; best lexical candidate Deficiency_of_Adenosine_Deaminase_2.yaml
Candidate DisMech targets Deficiency_of_Adenosine_Deaminase_2.yaml
Review date 2026-07-11

IEMbase phenotype signal

IEMbase labels this autosomal recessive record as ADA2-related adenosine deaminase 2 deficiency, with alternate name childhood-onset polyarteritis nodosa and abbreviation CECR1. The IEMbase signal is sparse but characteristic: very low plasma/deoxyadenosine deaminase activity, polyarteritis nodosa across age groups, and adult Sneddon syndrome.

DisMech phenotype coverage

Deficiency_of_Adenosine_Deaminase_2.yaml is the correct local target. It models biallelic ADA2/CECR1 loss of function, markedly reduced ADA2 activity, endothelial injury, vasculopathy, myeloid inflammatory dysregulation, emerging lysosomal DNA-editing/TLR9 immune-sensing biology, recurrent fever, livedo racemosa, early-onset ischemic and hemorrhagic stroke, polyarteritis nodosa-like vasculitis, hepatosplenomegaly, immunodeficiency, cytopenias, anti-TNF therapy, and hematopoietic stem cell transplantation.

Concordance and completeness

Judgement: false negative; exact local disease coverage exists.

The gene, CECR1 synonym, recessive inheritance, low enzyme activity, and polyarteritis nodosa identity are concordant. IEMbase's Sneddon syndrome row is best handled as a phenotype/overlap prompt within ADA2 vasculopathy, not as a reason to map the record to the separate local Sneddon_syndrome.yaml entry. The local DADA2 entry is much richer for mechanism, stroke, livedo, immune, and therapy coverage.

Curation actions

  • Treat Deficiency_of_Adenosine_Deaminase_2.yaml as exact local coverage for IEMbase 0790.
  • Preserve childhood-onset PAN and CECR1 as alternate naming for DADA2.
  • Consider reviewing whether Sneddon-like vasculopathy should be added as an explicit phenotype or discussion note in the local DADA2 entry.