Endocrine Abstracts

Background: Three 5α-reductase (5α-R1-3) isoenzymes are described. In humans, 5α-R2 deficiency (5α-R2D) causes pseudohermaphroditism and 5α-R3 neurological defects. The role of 5α-R1 is not clear. Urine steroid profiling (USP) by GC–MS can compare 5α-reduction activity based on excretion of 5α- and 5β-reduced metabolite ratios. Finasteride predominantly inhibits 5α-R2. USP in these patients shows concordance with 5α-R...

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...