5-alpha-reductase deficiency

5-alpha-reductase deficiency (5-ARD) is a condition caused by a mutationof the 5-alpha reductasetype 2 gene. This gene encodes an enzymethat converts testosteroneto dihydrotestosterone(DHT). DHT is necessary for the development of male genitaliain utero, and the resulting DHT deficency results in ambiguous external genitalia at birth. The condition affects only chromosomal males (i.e., those with XY chromosomes). Individuals with 5-ARD lack a uterusand Fallopian tubes(due to the normal action of Mullerian inhibiting factor), and possess testiclesand Wolffian structures. Their external genitalia, however, can vary from normal male external genitalia, to ambiguous genitalia, to normal female genitalia (although with a tendency towards an enlarged clitoris). In the later cases the Wolffian ductsterminate in the perineumor in a pseudovagina. 5-ARD constitutes a variety of intersexualism.

Individuals with 5-ARD have XY chromosomes and testicles, and tend to have a vaginaand labia, but with a small peniscapable of ejaculation instead of a clitoris (this penis, however, appears to be a clitoris at birth). These individuals are normally raised as girls. However, come puberty, their testes will descend, their voice will deepen and they often will develop a male sexual identity. However, they develop only limited facial hair, and will not experience male-pattern baldness.

Literature

• Jeffrey Eugenideswon a Pulitzer Prizefor his 2003novel Middlesex, which explores this deficiency.

Pop culture

• Quentin Costa, a character on the television show Nip/Tuck, has this condition.

External links

• OMIM264600
• 5-alpha-reductase deficiency

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It uses material from the http://en.wikipedia.org/wiki/5-alpha-reductase+deficiency Wikipedia article 5-alpha-reductase deficiency.