title: Steroidogenic isoenzymes in human hair and their potential role in androgenetic alopecia.
abstract: Androgenetic alopecia (AGA) is the most common type of hair loss. The relatively strong concordance of the degree of baldness in fathers and sons is not consistent with a simple Mendelian trait, and a polygenic basis is considered to be most likely. So far, the predisposing genes for AGA are unknown and we do not understand the molecular steps involved in androgen-dependent beard growth versus androgen-dependent hair loss, but AGA can be defined as a dihydrotestosterone (DHT)-dependent process with continuous miniaturization of sensitive hair follicles. The type 2 5alpha-reductase plays a central role by the intrafollicular conversion of testosterone to DHT. However, due to the increasing knowledge in this field, we now know that there are many more steroidogenic enzymes involved in the onset and development of AGA, and this article shall provide a critical overview of recent discoveries.
authors.affiliation: Department of Dermatology, Philipp University, Marburg, Germany. rolf.hoffmann@mailer.uni-marburg.de
authors.forename: Rolf
authors.initials: R
authors.lastname: Hoffmann
mesh_terms: D000505:Alopecia / Q000503:physiopathology*; D000728:Androgens / Q000502:physiology*; D001141:Aromatase / Q000502:physiology; D019314:Dehydroepiandrosterone Sulfate / Q000378:metabolism; D006197:Hair / Q000254:growth & development* / Q000502:physiology; D006801:Humans; D006913:Hydroxysteroid Dehydrogenases / Q000502:physiology; D008297:Male; D009097:Multienzyme Complexes / Q000502:physiology; D011375:Progesterone Reductase / Q000502:physiology; D011944:Receptors, Androgen / Q000502:physiology; D013251:Steroid Isomerases / Q000502:physiology*
chemical_list: C021425:3 beta-hydroxysteroid oxidoreductase-delta(5) 3-ketosteroid isomerase; D000728:Androgens; D009097:Multienzyme Complexes; D011944:Receptors, Androgen; D019314:Dehydroepiandrosterone Sulfate; D006913:Hydroxysteroid Dehydrogenases; D011375:Progesterone Reductase; D001141:Aromatase; D013251:Steroid Isomerases