POR and congenital adrenal hyperplasia: Congenital adrenal hyperplasia (CAH) is a set of monogenic autosomal recessive disorders resulting from pathogenic variants in genes encoding enzymes and/or proteins in the cortisol biosynthesis pathways: 21-hydroxylase (21OH), 11β-hydroxylase (11βOH), 17α-hydroxylase (17OH; also known as 17,20-lyase), 3β-hydroxysteroid dehydrogenase type 2 (3βHSD2), steroidogenic acute regulatory protein (StAR), P450 cholesterol side-chain cleavage enzyme (SCC), and P450 oxidoreductase (POR) (Fig. 1).