21-hydroxylasis
Steroidi 21-Hydroxylasis vel 21α-hydroxylasis (numerus EC 1.14.14.16) est simul enzymum hydroxylasis et cytochromate P450, quod steroida positione C21 gregem hydroxyli (-OH) addit, quod biosynthesis et aldosteroni et cortisoli perncesse est, quia intra reticuli endoplasmatic membranas corticis glandulae suprarenalis convertit progesteronum in 11-deoxycorticosteronum, velut 17α-hydroxyprogesteronum in 11-deoxycortisolum. In hominibus enzymi genum, CYP21A2, chromosomate 6 locatum est. Hodie plus quam 1 300 geni mutationes geneticae notae sunt. Hyperplasia glandularum suprarenalium congenitalis, grex morborum geneticorum cum malo conversionis cholesteroli in cortisolum, in plus qua, 90% deficientia enzymi 21-hydroxlasis causa observatur.