CYP26B1 and Antley-Bixler syndrome: Antley-Bixler syndrome with genital anomalies and disordered steroidogenesis (ABS1; OMIM 201750) is caused by biallelic variants in the POR gene (HGNC:9208) encoding cytochrome P450 oxidoreductase, the universal electron donor for all microsomal P450 enzymes, including CYP26B1.75