5 alpha reductase deficiency

5-alpha reductase is an enzyme that converts testosterone to dihydrotestosterone in tissues. This enzyme also participates in the synthesis of such neurosteroids as allopregnanolone and tetrahydrodeoxycorticosterone (THDOC), converts progesterone into dihydroprogesterone and (DHP), and deoxycorticosterone (DOC) into dihydrodeoxycosterone (DHDOC). The biochemistry deficiency of 5-alpha-reductase is characterized by low testosterone levels and low levels of dihydrotestosterone.

Dihydrotestosterone is a powerful androgen necessary for the intrauterine development of the male genitalia .

A deficiency of 5-alpha-reductase affects only genetic males, that is, carriers of the Y chromosome , since at the moment no role of this substance in the development of women has been identified ^[2] .

Deficient 5-alpha-reductase may have male, intermediate or female external genitalia. They are born with the male reproductive glands, including the testicles and wolf channels, but usually the other primary sexual characteristics of them are female. As a result, they are often brought up as girls, despite the male gender identity ^{[3] [4]} .

Usually, people with this syndrome are able to produce viable sperm ; feminized subjects tend to have clitoromegaly or micropenis ; the urethra can be connected to the phallus. Ejaculation and erection are possible, but the impossibility of producing coitus is often encountered.

During puberty in people with 5-alpha-reductase deficiency, amenorrhea is present and virilization occurs, including testicular prolapse, hirsutism (male hair growth, not to be confused with hypertrichosis ), decreased voice and clitoris enlargement. In adulthood, they are not susceptible to androgenetic alopecia ^[1] . Since dihydrotestosterone is a much more potent androgen than testosterone, virilization in subjects with 5-alpha-reductase deficiency may be absent or insignificant. There is a theory that an increase in testosterone levels during puberty can cause the production of dihydrotestosterone sufficient for the virilization (either through SRD5A1 , or the release of a certain amount of SRD5A2 by the testes).

Barreness

There is an increased risk of cryptorchidism as well as testicular cancer . There may be problems with fertility due to underdevelopment of the seminal vesicles and prostate .

On the other hand, pregnancy is impossible for them in the absence of a vagina (up to two thirds of the vagina can be present). Because of the action of the secreted by the testicles, uterus and fallopian tubes are absent in people with 5-alpha-reductase deficiency.

The proportion of people with 5-alpha-reductase deficiency varies in different parts of the Earth, in one small Dominican this mutation occurs in 12 of 13 families, and every 90th man is prone to 5-alpha reductase deficiency ^[5] .

• The Italian film Arianna tells the story of a person with this syndrome.
• In the third season of the series “ Parts of the Body, ” an episode of “Quentin Costa,” it is revealed that Dr. a 5-alpha reductase deficiency.
• In the novel “ Middle Gender ” Jeffrey Eugenides, the main character is gradually turning into a man because of this mutation.

• Intersex , Pseudo-Hermaphroditism

• OMIM article
• article on the resource eMedicine
• "Whatever I feel ..." article in "the New Internationalist"
• "Guevote: The Way I Feel Is How I Am" movie by Rolando Sanchez