POR
Chr 7ARcytochrome p450 oxidoreductase
Also known as: CPR, CYPOR, P450R
The protein functions as an endoplasmic reticulum oxidoreductase that transfers electrons from NADPH to cytochrome P450 enzymes, which are essential for steroid hormone metabolism, drug metabolism, and xenobiotic processing. Mutations cause autosomal recessive disorders including Antley-Bixler syndrome with genital anomalies and disordered steroidogenesis, as well as isolated disordered steroidogenesis due to cytochrome P450 oxidoreductase deficiency. These conditions primarily affect steroid hormone production and bone development, with genital anomalies and congenital adrenal hyperplasia being key clinical features.
Definitive — sufficient evidence for diagnostic panels
Population Genetics & Constraint
gnomAD v4 — loss-of-function & missense intolerance
Typical tolerance to LoF variation
Tolerant to missense variation
The highest-scoring mechanism for this gene is gain-of-function.
Note: In-silico variant effect predictors (SIFT, PolyPhen, REVEL, CADD) may underestimate pathogenicity of missense variants in genes with GOF or DN mechanisms. Consider functional evidence and clinical context.
Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312.
ClinVar Variant Classifications
700 submitted variants in ClinVar
Classification Summary
Curated Variants Distribution
Classified variants from ClinVar · 5 ACMG categories
| Classification | LoF | Missense + Inframe | Non-coding | Synonymous | Total |
|---|---|---|---|---|---|
Pathogenic | 41 | 3 | 25 | 0 | 69 |
Likely Pathogenic | 27 | 4 | 5 | 0 | 36 |
VUS | 3 | 120 | 30 | 0 | 153 |
Likely Benign | 1 | 1 | 177 | 196 | 375 |
Benign | 0 | 0 | 13 | 2 | 15 |
Conflicting | — | 29 | |||
| Total | 72 | 128 | 250 | 198 | 677 |
LoF = frameshift, stop gained/lost, canonical splice · Counts from ClinVar esearch · Updated hourly
View in ClinVar →Protein Context — Lollipop Plot
POR · protein map & ClinVar variants
Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.
3D Protein StructureAlphaFold
External Resources
Links to major genomics databases and tools
Clinical Trials
Active and recruiting trials from ClinicalTrials.gov
A Study of Encorafenib Plus Cetuximab With or Without Chemotherapy in People With Previously Untreated Metastatic Colorectal Cancer
ACTIVE NOT RECRUITINGCARE-CRC: Microbiome Insights and Correlations for Risk and Outcomes in Colorectal Cancer
NOT YET RECRUITINGGenetic Bases of Neuroendocrine Neoplasms in Mexican Patients
RECRUITINGStudy of Selected X-linked Disorders: Goltz Syndrome
ACTIVE NOT RECRUITINGExercise in Hereditary ATTR (ATTRv) Amyloidosis
RECRUITINGExternal Resources
Links to major genomics databases and tools