Endocrine Abstracts

CYP17A1 is a key enzyme of human steroidogenesis, which is unique in that it catalyses two reactions, 17-hydroxylase activity converting pregnenolone and progesterone to 17-hydroxypregnenolone (17Preg) and 17-hydroxy-progesterone, respectively, and 17,20 lyase activity, responsible for the conversion of 17Preg to dehydroepiandrosterone the crucial precursor of human sex steroid biosynthesis. 17-hydroxylase deficiency, a variant of congenital adrenal hyperplasia, results in glu...

The steroid 17α-hydroxylase enzyme CYP17A1 exerts two distinct activities that catalyze conversion reactions at key branch points in steroidogenesis. CYP17A1 17α-hydroxylase activity is the key step in cortisol synthesis whereas CYP17A1 17, 20 lyase activity generates sex steroid precursors. Inactivating CYP17A1 mutations result in CYP17A1 deficiency (17OHD), a rare form of congenital adrenal hyperplasia that classically presents with combined glucocorticoid and sex ...

Congenital adrenal hyperplasia (CAH) due to steroid 21-hydroxylase (CYP21A2) deficiency is the commonest inborn error in steroid hormone biosynthesis and the most frequent cause of congenital adrenal hyperplasia. The classic forms of 21-hydroxylase deficiency, salt-wasting (SW) and simple virilising (SV), usually present in the neonatal period with some simple virilising patients presenting later in childhood with precocious pseudopuberty. The non-classic form (NCCAH) mostly m...

Steroid 17α-hydroxylase (CYP17A1) exerts two distinct activities that catalyze conversion reactions at key branch points in steroidogenesis. CYP17A1 17α-hydroxylase activity is the key step in cortisol synthesis whereas CYP17A1 17,20 lyase activity generates sex steroid precursors. Inactivating CYP17A1 mutations result in CYP17A1 deficiency (17OHD), a rare form of congenital adrenal hyperplasia that classically presents with combined glucocorticoid and sex steroid de...