Mutations in POR (P450 (cytochrome) oxidoreductase, an essential electron donor to enzymes participating in cholesterol biosynthesis), have been identified in some patients with the ABS phenotype.
Individuals with an Antley-Bixler syndrome-like phenotype presenting with sexual ambiguity or other abnormalities in steroidogenesis should be analyzed for P450 oxidoreductase deficiency.
The knockout of cholesterogenic Cyp51 is embrionally lethal, with symptoms of Antley-Bixler syndrome occurring in mice, whereas the evidence for this association is conflicting in humans.
Numerous mutations/polymorphisms of the POR gene, encoding NADPH:cytochrome P450 oxidoreductase (CYPOR), have been described in patients with Antley-Bixler syndrome (ABS), presenting with craniofacial dysmorphogenesis, and/or disordered steroidogenesis, exhibiting ambiguous genitalia.