What if they do in fact have a Y chromosome, but their body fails to respond to it? Then they will grow up as if they were females. Also, due to chimerism (I g

What if they do in fact have a Y chromosome, but their body fails to respond to it? Then they will grow up as if they were females. Also, due to chimerism (I guess that’s what you are getting at with your last two sentences) even genetic sex-determination is only probabilistic — they try to find several Y chromosomes to identify someone’s sex as male.