IEMbase 0335: SRD5A3-related steroid 5-alpha-reductase 3 deficiency
Scope
| Field | Value |
|---|---|
| IEMbase ID | 335 |
| Nosology | 18.4.03.01 |
| Gene | SRD5A3 |
| External IDs | OMIM:612379; ORPHA:324737 |
| Generated mapping | CANDIDATE; 46_XY_DSD_Due_to_5_Alpha_Reductase_2_Deficiency.yaml |
| Candidate DisMech targets | Reject 46_XY_DSD_Due_to_5_Alpha_Reductase_2_Deficiency.yaml |
| Review date | 2026-07-07 |
IEMbase phenotype signal
IEMbase represents SRD5A3-CDG/CDG-Iq, also described as ocular coloboma with ichthyosis, brain malformations, and endocrine abnormalities. Characteristic rows include cataract, coloboma, erythroderma, facial dysmorphism, axial hypotonia, and midline brain malformations. Additional clinical rows include cerebellar abnormalities, dry skin, failure to thrive, growth hormone deficiency, hypotonia, ichthyosis, kyphosis, microphthalmia, nystagmus, and optic atrophy.
The biochemical rows include increased transaminases, type I sialotransferrins, increased partial thromboplastin time, decreased antithrombin III, decreased protein C and protein S, decreased dolichol phosphate, and decreased dolichol-linked Glc3Man9GlcNAc2. No treatment rows are present.
DisMech phenotype coverage
The generated candidate is the SRD5A2 46,XY disorder of sex development entry. It is not a valid target. That file models impaired conversion of testosterone to dihydrotestosterone caused by SRD5A2 loss, with undervirilization and pubertal virilization. It does not cover SRD5A3, dolichol-linked glycosylation, CDG-Iq, ocular coloboma/ichthyosis/brain-malformation syndrome, or the coagulation-factor biochemical profile.
Local CDG context is relevant at the module level, but no standalone SRD5A3-CDG entry exists.
Concordance and completeness
Judgement: true local disease gap; reject the SRD5A2 DSD candidate.
The mapping was likely driven by the "5 alpha-reductase" phrase. The two diseases are gene- and mechanism-distinct: SRD5A2 is an androgen-metabolism DSD, whereas SRD5A3-CDG affects dolichol/dolichol-phosphate-linked glycosylation.
Curation actions
- Add a standalone SRD5A3-CDG target before treating this record as mapped.
- Do not map to SRD5A2-related 46,XY DSD despite the overlapping enzyme-name phrase.
- Preserve ocular, dermatologic, brain-malformation, growth/endocrine, dolichol, transferrin, and anticoagulant-protein rows as future-curation prompts.