It's so absurd that transphobes say sex is chromosomes because the overwhelming majority of them are taking someone's word for it that their own chromosomes match their gender. I've certainly never seen mine.

I want to clap back with "how do you know you have a brain? you assume you have one, but have you ever opened up your skull and physically seen it?"

It's amazing how much misinformation there is about DSDs that people think that there could be millions, maybe billions, of people walking around, maybe you, me, the guy tweeting, who have a genetic defect relating to their sex chromosomes. Like that's so common, and isn't such a big deal that it wouldn't be extremely noticeable and make a massive difference to your life. Incidentally you can order karyotype testing kits online, I'd like to challenge one of these, or one of those TRAs that self-diagnose a DSD, to take one. I'll volunteer! I can guarantee XX, because if I were anything else it would be obvious in my life so far, my body would be quite different, in function and likely appearance.