Gender is a spectrum and not a binary. Gender is socially constructed and may be defined and expressed differently depending on the person. Sex however is not. Sex is biologically defined by the presence or absence of a Y chromosome, which affects hormones, body structure, genitalia etc. Even intersex individuals, while a bit more complicated, are assigned to the gender that most closely resembles them (genetically, genitalia-wise, and hormonally) at birth. They may present otherwise later tho
Yeah you’re right, it’s called aneuploidy. The first example is the only monosomy survivable and causes Turners Syndrome, and carriers are female. The second is triple x syndrome and many with Triple X have few or no noticeable symptoms and may not even know they have the condition. Trisomy afaik cause disorders not sex change. The last is so rare idk why mention it but same thing - all male no sex change. Even if chromosomes aren’t sex still is.