IEMbase 0110: ALAS2-related erythroid 5-aminolevulinate synthase deficiency
Scope
| Field | Value |
|---|---|
| IEMbase ID | 110 |
| Nosology | 17.1.01.01 |
| Gene | ALAS2 |
| External IDs | OMIM:300751; ORPHA:75563 |
| Generated mapping | UNMAPPED |
| Candidate DisMech targets | None for a disease entry; contextual mention in Myopathy_Lactic_Acidosis_and_Sideroblastic_Anemia.yaml differential diagnosis |
| Review date | 2026-07-07 |
IEMbase phenotype signal
IEMbase represents this as ALAS2-related erythroid 5-aminolevulinate synthase deficiency, with alternate labels X-linked recessive sideroblastic anemia type 1 and XLSA. Treatability is marked unknown, though the treatment table lists hemin with low-level evidence.
The cached JSON has no characteristic biochemical rows. The non-characteristic clinical rows are dysmorphic erythrocytes, liver dysfunction, and increased bone-marrow sideroblasts, with adolescent/adult onset patterning.
DisMech phenotype coverage
There is no curated DisMech disease entry for ALAS2-related sideroblastic
anemia. Inherited_Porphyria.yaml contains ALAS2-related X-linked
protoporphyria, but that is the opposite ALAS2 direction: erythroid ALAS2
superactivity/gain of function with protoporphyrin accumulation and
photosensitivity. It should not be reused for ALAS2 deficiency.
Myopathy_Lactic_Acidosis_and_Sideroblastic_Anemia.yaml mentions X-linked
sideroblastic anemia only as a differential diagnosis for ALAS2-related pure
sideroblastic anemia without mitochondrial myopathy. That is useful context,
but it is not phenotype coverage for a standalone XLSA disease model.
Concordance and completeness
Judgement: true unmapped disease gap.
The IEMbase record is sparse but points to a distinct hematologic heme-synthesis disorder centered on ring sideroblasts and erythroid morphology, not a porphyria. DisMech currently has related heme and sideroblastic-anemia context, but no ALAS2-deficiency entry that could be assessed for concordant phenotypes.
Curation actions
- Do not map this to ALAS2-related X-linked protoporphyria.
- Consider a future standalone X-linked sideroblastic anemia / ALAS2 deficiency entry if sideroblastic anemia scope is expanded.
- Reuse the MLASA differential-diagnosis note only as context, not as a canonical target.