IEMbase 0198: POR-related cytochrome P450 oxidoreductase deficiency
Scope
| Field | Value |
|---|---|
| IEMbase ID | 198 |
| Nosology | 24.2.07.01 |
| Gene | POR |
| External IDs | OMIM:201750; ORPHA:83 |
| Generated mapping | MAPPED; Amniotic_Band_Syndrome.yaml |
| Candidate DisMech targets | No direct target; Humeroradial_Synostosis.yaml has partial Antley-Bixler/POR context |
| Review date | 2026-07-07 |
IEMbase phenotype signal
IEMbase represents this as POR-related cytochrome P450 oxidoreductase deficiency, with alternate labels Antley-Bixler syndrome and ABS. Treatability is marked unknown.
The biochemical rows include normal-to-increased ACTH, normal-to-increased 17-OH-pregnenolone, neonatal elevation of 17-OH-progesterone, neonatal androgen/androstenedione/testosterone excess followed by low-to-normal values later, decreased ACTH-stimulated cortisol with normal baseline cortisol, neonatal DHEA excess followed by low-to-normal values later, and increased urinary pregnanediol. Characteristic clinical rows include femoral bowing and fractures, midface hypoplasia, radiohumeral synostosis, and radioulnar synostosis. Additional rows include adrenal insufficiency, ambiguous genitalia, 46,XY undervirilization, neonatal androgen excess, Antley-Bixler syndrome, arachnodactyly, choanal atresia or stenosis, clitoral hypertrophy, craniosynostosis, dysplastic ears, hydronephrosis, hypoplastic labia majora, hypospadias, male genital hypoplasia, phalangeal malformations, renal anomalies or hypoplasia, scoliosis, skeletal abnormalities, and Prader III-V virilization in 46,XX individuals. No treatment rows are listed.
DisMech phenotype coverage
Amniotic_Band_Syndrome.yaml is not a valid target. The generated exact mapping
is an acronym collision: IEMbase uses ABS for Antley-Bixler syndrome, whereas the
local file models amniotic band syndrome, a sporadic mechanical malformation
sequence. Humeroradial_Synostosis.yaml contains relevant partial context for
POR-related Antley-Bixler syndrome and radiohumeral synostosis, but it is an
HRS feature entry, not a canonical POR deficiency disease entry and it does not
cover the steroidogenesis phenotype in full.
Concordance and completeness
Judgement: mapped false positive; true POR deficiency/Antley-Bixler local gap with partial HRS context.
IEMbase describes a POR-specific mixed steroidogenesis and skeletal malformation disorder: disordered adrenal/gonadal steroid markers, adrenal insufficiency, genital ambiguity, craniosynostosis, midface hypoplasia, radiohumeral/radioulnar synostosis, femoral bowing/fractures, choanal abnormalities, and renal anomalies. Local amniotic band syndrome is unrelated; local HRS captures only one important skeletal feature and contextual gene association.
Curation actions
- Do not map this record to
Amniotic_Band_Syndrome.yaml. - Consider a future POR-related cytochrome P450 oxidoreductase deficiency /
Antley-Bixler syndrome entry, with
Humeroradial_Synostosis.yamlretained as feature context rather than the disease target. - Seed that future entry with ACTH-stimulated cortisol deficiency, mixed neonatal androgen excess and later androgen deficiency, DHEA/pregnanediol abnormalities, adrenal insufficiency, genital ambiguity, craniosynostosis, midface hypoplasia, radiohumeral/radioulnar synostosis, femoral bowing, and choanal/renal anomalies.