Does having a Y chromosome make someone a man?
A lot of unintended harm happens when people assume a Y chromosome makes a person a boy or a man and the lack of a Y chromosome makes a person a girl or a woman. For example, one physician educator on our “Medical Advisory Board”:/about/medicalboard had the challenging experience of trying to calm a 23-year-old patient who had just been told by a resident that she was “really a man” because the resident had diagnosed the patient as having a Y chromosome and complete “androgen insensitivity syndrome”:/faq/conditions/ais (CAIS). It is true that in typical male development, the SRY gene on the tip of the Y chromosome helps to send the embryo down the masculine pathway. But more than the SRY is needed for sex determination and differentiation; for example, women with CAIS have the SRY gene but lack androgen receptors. In terms of hormone effects on their bodies (including their brains), women with CAIS have had much less “masculinization” than the average 46,XX woman because their cells do
