Di-hydrotestosterone or DHT as it is known is a very potent hormone in the human body. This hormone DHT is responsible for giving man his male characteristics when he is just a foetus in his mother’s womb. To put things in the simplest of ways, all of us start out in the womb as females, a status decided on by nature. It is during the sixth week of pregnancy that DHT begins to form in the foetus by testosterone, the male hormone, combining with an enzyme called 5 alpha reductase. It is this DHT that stimulates the growth of the male sex organs and stems the growth of the female genitalia. Now just imaging what would happen if this DHT were to be a scarce commodity during this crucial stage of sex determination in the foetus!
The anomalies of DHT deficiency
The result of a deficiency of Di-hydrotestosterone in the foetus stage will result in abnormal formation of male sex organs and will produce an infant which will be neither this way nor that, and if the male genitalia are fully formed then there may just be a lack of libido and probably complete sterility. Let us understand how this happens. Because males with a deficiency of Di-hydrotestosterone are born with ambiguous genitalia, this condition is better known as ‘Pseudohermaphroditism’ the clinical abnormalities of this condition will range from infertility to underdeveloped male with ‘Hypospadias’ to predominantly developed female external genitalia. The uterus and fallopian tubes in this case are absent because of the normal secretion of the ‘müllerian-inhibiting’ factor and the testes are intact. Male internal ducts are present but terminate in a blind Pseudovaginal pouch or terminate on the perineum.
How it happens
5-alpha-reductase, the enzyme that converts testosterone to Di-hydrotestosterone or DHT, is the cause of this very disturbing disorder. The conversion to DHT involves hydroxylation at the 5 carbon position of the ‘A’ ring of the steroid molecule. This change flattens the shape of DHT, permitting it to fit perfectly into the androgen receptor in a way that the hormone testosterone cannot. In this way, DHT is bound selectively to the androgen receptors in genital skin and fibroblasts, making its action necessary for the development of normal male genital anatomy in the foetus.