IEMbase 0562: OAT-related ornithine aminotransferase deficiency
Scope
| Field | Value |
|---|---|
| IEMbase ID | 562 |
| Nosology | 1.7.1.01 |
| Gene | OAT |
| External IDs | OMIM:258870; ORPHA:414 |
| Generated mapping | MAPPED; ornithine_aminotransferase_deficiency.yaml |
| Candidate DisMech targets | ornithine_aminotransferase_deficiency.yaml |
| Review date | 2026-07-07 |
IEMbase phenotype signal
IEMbase represents OAT-related ornithine aminotransferase deficiency, with alternate labels gyrate atrophy of the choroid and retina, hyperornithinemia, and OAT/GACR. The record is autosomal recessive and treatable. Treatment rows include pyridoxine, creatine, lysine, and a protein-defined diet with arginine-free supplementation of essential amino acids.
Biochemical rows include very high plasma and urinary ornithine, urinary arginine and lysine elevations, low creatine across CSF, plasma, and urine, low brain or muscle creatine/phosphocreatine ratio, low guanidinoacetic acid across CSF, plasma, and urine, mostly normal ammonia except neonatal normal-high values, low-normal plasma creatinine, abnormal liver mitochondria, and a high neonatal proline/citrulline ratio. Clinical and characteristic rows include gyrate choroid and retinal atrophy, night blindness, myopia, tunnel vision, chorioretinal degeneration, cataract, blindness, retinal detachment, intellectual disability, seizures, muscle weakness, neuropathy, and brain imaging abnormalities.
DisMech phenotype coverage
ornithine_aminotransferase_deficiency.yaml is the correct local target. The
entry models autosomal recessive OAT dysfunction, impaired mitochondrial
matrix ornithine transamination, decreased L-ornithine catabolism, marked
hyperornithinemia, secondary amino-acid and creatine depletion, progressive
chorioretinal degeneration, retinal pigment epithelial cell injury, myopia,
cataract, night blindness, constricted visual fields, and progressive visual
loss.
Concordance and completeness
Judgement: correct high-concordance mapping to
ornithine_aminotransferase_deficiency.yaml.
IEMbase and DisMech agree on OAT identity, recessive inheritance, hyperornithinemia, mitochondrial ornithine aminotransferase dysfunction, secondary creatine depletion, gyrate chorioretinal atrophy, night blindness, myopia, cataract, constricted visual fields or tunnel vision, and progressive vision loss. DisMech is stronger for the mechanistic chain from OAT loss to hyperornithinemia and retinal injury.
IEMbase adds detailed biochemical prompts for urinary arginine and lysine, guanidinoacetic acid, creatine/phosphocreatine ratio, creatinine, neonatal ammonia and proline/citrulline ratio, plus neuromuscular, seizure, neuropathy, retinal-detachment, and imaging rows.
Curation actions
- Keep this record mapped to
ornithine_aminotransferase_deficiency.yaml. - Review the IEMbase treatment rows, especially arginine restriction, pyridoxine responsiveness, creatine supplementation, and lysine supplementation, against local treatment scope.
- Consider source-checking IEMbase neuromuscular, seizure, neuropathy, retinal-detachment, and detailed creatine/GAA rows before import.