POR is a 2-flavin protein that is responsible for the transfer of electrons from NADPH to all 50 microsomal cytochrome P450 (CYP450) enzymes.
[3] Virilization of female infants in PORD may also be caused by alternative biosynthesis of 5α-dihydrotestosterone via the so-called "androgen backdoor pathway".
[5][6] The ABS component of severe forms of PORD is probably caused by CYP26B1 deficiency, which results in retinoic acid excess and defects during skeletal embryogenesis.
[3] All forms of PORD in humans are likely partial, as POR knockout in mice results in death during prenatal development.
[3] Symptoms of severe forms of PORD include ambiguous genitalia in males and females, congenital adrenal hyperplasia, cortisol deficiency, and Antley–Bixler skeletal malformation syndrome (ABS), while symptoms of mild forms include polycystic ovary syndrome in women and hypogonadism in men.