Intersex in the House

A post in three parts:


Part I: Confronting the Issues:

While this video is fictional, from the TV series "House Private Practice" - yes, this happens. In the USA, in England, and in Australia.



When I saw it for the first time, I teared up. Not from my personal experience as a baby, for I looked unambiguously male at birth.

My son... had to have genital reconstruction at 18 months. He was in increasing pain. He's Intersex too, very mildly.


Part II - endocrinology for dummies

11-beta-hydroxylase deficiency is a rare form of Congenital Adrenal Hyperplasia.

I'll try to explain things as best I understand them, given that I'm no enocrinologist. You really need to see this diagram first:



That shows the chains by which cholesterol is changed into various hormones, and their precursors. The green and red horizontal and vertical bars show the enzymes necessary to help along the conversion.

To simplify, only cortisol, testosterone (the main male sex hormone), dihydrotestosterone (the super-virilising hormone that causes male-pattern baldness), estrone (a mild female hormone), and both estrodiol and estriol, (main female sex hormones) will be looked at.

For example: 17-beta-hydroxysteroid-dehydrogenase (17BHD) - the long green horizontal bar near the bottom - is needed to convert dehydroepiandrosterone into androstendiol (which then in turn gets converted to testosterone), androstenedione into testosterone, and estrone into estrodiol.

Total 17BHD deficiency means "you can't get there from here" as regards testosterone production. Mildly feminising estrone is the only sex hormone being produced. However, most cases are partial, and once you get some testosterone being produced, as happens in puberty, some gets changed to the super-virilising dihydrotestosterone. So 46XY people born looking like girls because they didn't have much testosterone exposure in the womb virilise to look somewhat male.

5-alpha-reductase deficiency (5ARD) is even more "targeted" if you like, and explains the subtle differences between 5ARD and 17BHDD. Both can cause a "natural sex change" from female looking at birth to male looking later, but the change in 5ARD people is more complete, as it's only the production of dihydrotestosterone that's blocked.

Now see the red vertical bar on the far right. 11-beta-hydroxylase. It's needed to produce corticosterone from deoxycorticosterone, and cortisol from 11-deoxycortisol.

Low cortisol is a life-threatening condition, so in foetal development, the adrenal glands enlarge to compensate by producing more of the precursors to cortisol.

Because 11β-hydroxylase activity is not necessary in the production of sex steroids (androgens and estrogens), the hyperplastic adrenal cortex produces excessive amounts of DHEA, androstenedione, and especially testosterone.

These androgens produce effects that are similar to those of 21-hydroxylase deficient CAH. In the severe forms, XX (genetically female) fetuses can be markedly virilized, with ambiguous genitalia that look more male than female, though internal female organs, including ovaries and uterus develop normally.

If the leftmost vertical bar, 3-beta-hydroxysteroid-dehydrogenase (3BHD), is deficient... pretty much any darn thing can happen, the whole system's out of whack. Mild 3BHD deficiency can cause all sorts of effects. Trust me on that. But I digress...

The point is, 11-beta-hydroxylase deficiency causes virilisation of 46XX people. Some - about 10% - end up with male gender identities.


Part III - Some advice for parents in this position.

1. Pick a sex, any sex. Socially (not surgically) assign your child to that for now. It won't do any harm if it's wrong, sex is in the brain, sex of rearing doesn't matter.

2. Be prepared at any time from age 2 onwards (median is 5) for your child to say that a silly mistake has been made, that she's really a boy, or he's really a girl. Change sex of rearing accordingly.

3. Many people with ambiguous genitalia are happy with things that way. More are not, and desire corrective surgery, one way or the other. Your duty as parents is to bow to the inevitable, and supply resources and options so your child can have, or not have, surgery as they choose.