PPOX
Chr 1ADARprotoporphyrinogen oxidase
Also known as: PPO, V290M, VP, VPCO
The protein catalyzes the 6-electron oxidation of protoporphyrinogen IX to protoporphyrin IX as the penultimate enzyme in heme biosynthesis, located on the inner mitochondrial membrane. Mutations cause variegate porphyria, a disorder of heme metabolism that can present with childhood onset or later in life. Inheritance is autosomal dominant, though autosomal recessive forms have also been reported.
Strong evidence — appropriate for clinical testing
Population Genetics & Constraint
gnomAD v4 — loss-of-function & missense intolerance
More LoF-intolerant than ~75% of genes
Mild missense constraint
The highest-scoring mechanism for this gene is dominant-negative.
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
0 submitted variants in ClinVar
Protein Context — Lollipop Plot
PPOX · 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
Orexin Gene in Anorexia Nervosa
RECRUITINGThe Effect of Different Diets on Arterial Stiffness in Obese Patients on Semaglutide
RECRUITINGAcute Porphyria Biomarkers for Disease Activity
ACTIVE NOT RECRUITINGGenetic and Clinical Characterization of Type 1 and 2 Narcolepsy in Adult and Pediatric Black and North African Populations
NOT YET RECRUITINGExternal Resources
Links to major genomics databases and tools