Carole Hooven, Ph.D.

A lot of people just think, of course, that applies also to humans, but it can't apply to humans because our alpha-fetoprotein does not effectively bind estrogen.

We also have men who can't produce aromatase and don't have estrogen, and they are fully typically masculine in their behavior.

They have other issues like with bone inflammation.

And we also have complete androgen insensitivity syndrome, where you have XY individuals who have testicles but have a defective androgen receptor and essentially develop.

They have testicles and XY sex chromosomes and high testosterone, but they develop as females because their testosterone is converted into estrogen.

So they have no testosterone whatsoever, yet they do have estrogen.

They're exposed to maternal estrogens.

They're very feminine.

So they go through female, essentially female puberty, and many of them will discover that they have testes and XY sex chromosomes when they don't get their period.

So they're like very feminine.

But the point here is that we know for sure this is the case in non-human primates.

Totally feminine.

Totally feminine.

So this is interesting because this is a point mutation in the androgen receptor gene.

One small mutation.

Everything else is just typical.

male.

You just get the one mutation in the androgen receptor that is disabling it, and you take what would have been a typical male, and you have someone with testes and XY sex chromosomes.

You don't have the double X, you have all the genes on the Y, but you have a totally typical, for all intents and purposes, girl and then a woman.

Totally.