Endocrine Abstracts

Background: 5α-Reductase type 2 deficiency (5ARD) is caused by mutations in the SRD5A2 gene. Inadequate masculinisation in XY individuals results from failure to convert testosterone (T) to dihydrotestosterone (DHT), a potent androgen. A decreased serum T:DHT ratio is frequently taken to identify 5ARD, but requires hCG stimulation for prepubertal patients; findings are not always supported by genotyping. Urine steroid profiling (USP) by GC-MS is established as showing sig...

Cytochrome P450 side-chain cleavage enzyme (CYP11A1) catalyses the first and rate-limiting step of steroidogenesis. CYP11A1 firstly converts cholesterol into 22R-hydroxycholesterol, which relies on mitochondrial steroidogenic acute regulatory protein (StAR)-mediated cholesterol import. Two further StAR-independent CYP11A1 reactions facilitate pregnenolone biosynthesis. CYP11A1 deficiency is rare and manifests with adrenal insufficiency (AI), and, in 46,XY individuals, with nor...