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IEMbase 0160: UPB1-related beta-ureidopropionase deficiency

Scope

Field Value
IEMbase ID 160
Nosology 16.1.03.02
Gene UPB1
External IDs OMIM:613161; OMIM:606673; ORPHA:65287
Generated mapping UNMAPPED
Candidate DisMech targets Beta-Ketothiolase_Deficiency.yaml
Review date 2026-07-07

IEMbase phenotype signal

IEMbase represents this as UPB1-related beta-ureidopropionase deficiency. Treatability is marked unknown.

The biochemical rows are pyrimidine catabolism markers: increased plasma and urinary dihydrothymine, increased plasma and urinary dihydrouracil, increased plasma and urinary N-carbamyl-beta-alanine, and increased plasma N-carbamyl-beta-aminoisobutyric acid. The clinical rows are variable and include psychomotor delay, seizures, dystonia, hypotonia, speech disturbances, dysmorphic features, hypertelorism, and strabismus.

DisMech phenotype coverage

There is no local standalone UPB1/beta-ureidopropionase deficiency entry.

Beta-Ketothiolase_Deficiency.yaml is a false candidate. It is an ACAT1 disorder of isoleucine catabolism and ketone-body handling, with ketoacidotic crises and isoleucine-derived organic acid markers. It does not model UPB1, dihydropyrimidine catabolism, N-carbamyl-beta-alanine, dihydrothymine, or dihydrouracil accumulation.

Concordance and completeness

Judgement: true local gap.

The generated candidate appears to be a broad organic-acid/neurologic neighbor rather than a disease match. IEMbase 160 is specifically a pyrimidine catabolism disorder with UPB1 and beta-ureidopropionase biochemical markers. Current DisMech coverage does not capture it.

Curation actions

  • Leave IEMbase 160 unmapped for now.
  • Future curation should create a UPB1/beta-ureidopropionase deficiency entry if this disease is in scope.
  • Use the IEMbase N-carbamyl-beta-alanine, N-carbamyl-beta-aminoisobutyric acid, dihydrothymine, dihydrouracil, seizures, hypotonia, dystonia, and psychomotor-delay rows as primary leads.