Steroid 5 alpha-reductase 2 deficiency

Endocr Rev. 1993 Oct;14(5):577-93. doi: 10.1210/edrv-14-5-577.


In the 20 yr since it was established that impairment of dihydrotestosterone formation is the cause of a rare form of human intersex, a wealth of information has accumulated about the genetics, endocrinology, and variable phenotypic manifestations, culminating in the cloning of cDNAs encoding two 5 alpha-reductase genes and documentation that mutations in the steroid 5 alpha-reductase 2 gene are the cause of 5 alpha-reductase deficiency. Perplexing and difficult problems remain unresolved, e.g. whether the variability in manifestations is due to variable expressions of steroid 5 alpha-reductase 1 or to effects of testosterone itself. It is also imperative to establish whether defects in steroid 5 alpha-reductase 2, perhaps in the heterozygous state, are responsible for a portion of cases of sporadic hypospadias, to determine whether 5 alpha-reductase plays a role in progesterone action in women, and to elucidate the relation between androgen action and gender role behavior.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.
  • Review

MeSH terms

  • 3-Oxo-5-alpha-Steroid 4-Dehydrogenase / deficiency*
  • 3-Oxo-5-alpha-Steroid 4-Dehydrogenase / genetics
  • 3-Oxo-5-alpha-Steroid 4-Dehydrogenase / metabolism
  • Androgens / pharmacology
  • Androgens / physiology
  • Dihydrotestosterone / metabolism
  • Disorders of Sex Development / enzymology
  • Disorders of Sex Development / genetics
  • Estrogens / physiology
  • Female
  • Gender Identity
  • Humans
  • Male
  • Phenotype
  • Sex Differentiation


  • Androgens
  • Estrogens
  • Dihydrotestosterone
  • 3-Oxo-5-alpha-Steroid 4-Dehydrogenase