[noneeeed]

Just to add one more wrinkle to the link between DNA and the presentation of sex, there is also androgen insensitivity syndrome, in which the person has a Y chromosome, but the developing body does not react to the testosterone produced by the testes.

The result is someone who may appear to be female, have female genitals, but has testes where ovaries would be expected. It's often not discovered until puberty doesn't happen as expected, and they discover they can't have children.

Like all these conditions, this is on something of a spectrum depending on how total it is.

As you say, genes are complicated. So much more so than is often implied in reporting of discoveries of "a gene for X".