Ambiguous genitalia look neither male nor female, but instead is a mix of the two, or is a mix when considered with the chromosomes of the individual. This is what is usually referred to when speaking of Intersex or DSD (disorder of sexual development, though clearly agenesis fits here too). A baby with XX or female pattern chromosomes may be born with what looks like a complete penis but empty scrotum. This is the extreme presentation of CAH, congenital adrenal hyperplasia. A baby with XY or male pattern chromosomes may be born with what looks like normal female genitals, but a shallow or “blind” vagina that does not lead to a uterus. This is the presentation of AIS, (complete) androgen insensitivity syndrome. PAIS, partial androgen insensitivity, can lead to an array of genital differences, all along the spectrum between male and female. Incomplete CAH, can lead to a variety of partially masculinized genitals, also all along the spectrum.