IEMbase 0035: PSAT1-related phosphoserine aminotransferase deficiency
Scope
| Field | Value |
|---|---|
| IEMbase ID | 35 |
| Nosology | 1.6.02.01 |
| Gene | PSAT1 |
| External IDs | OMIM:610992; OMIM:610936 |
| Generated mapping | UNMAPPED; best fuzzy candidate ornithine_aminotransferase_deficiency.yaml |
| Candidate DisMech targets | none currently valid |
| Review date | 2026-07-07 |
IEMbase phenotype signal
IEMbase represents PSAT1 deficiency as another serine-biosynthesis disorder. The biochemical pattern is low CSF serine, low plasma serine, low CSF glycine, and low plasma glycine.
The phenotype signal is severe and early: intractable seizures, neonatal seizures, hypertonia, microcephaly, generalized atrophy on MRI, and cerebellar vermis hypoplasia on MRI. Nutritional glycine and L-serine are listed as treatments.
DisMech phenotype coverage
There is no current DisMech entry or subtype for PSAT1-related phosphoserine
aminotransferase deficiency. The generated fuzzy candidate,
ornithine_aminotransferase_deficiency.yaml, is not a valid match. OAT
deficiency is gyrate atrophy of the choroid and retina with hyperornithinemia
and progressive ophthalmologic decline; PSAT1 deficiency is a serine-synthesis
encephalopathy with low serine/glycine and early seizures.
Concordance and completeness
Judgement: generated unmapped status is correct, and the OAT candidate should be rejected.
IEMbase is useful for future curation because it distinguishes PSAT1 deficiency from the broader serine-deficiency group by its low glycine signal and MRI findings, especially cerebellar vermis hypoplasia and generalized atrophy.
Curation actions
- Do not map this record to ornithine aminotransferase deficiency.
- Consider a future serine-biosynthesis disorder grouping or entry set for PHGDH, PSAT1, and PSPH.
- If curated, keep PSAT1-specific low glycine and cerebellar vermis hypoplasia separate from the more general low-serine phenotype.