Chapter 7, Problem 1CS

Gender is someone’s conscious and unconscious feelings of belonging to one sex or another. Each year, about 1 in 4500 children are born with a disorder involving sexual development, where the chromosomal, gonadal, or anatomical sex is atypical. Here we will consider two similar cases with different outcomes. In case 1, a 2-year-old child displayed a mosaic chromosome composition of 45, X/46, XY, with one ovary, one testis, a uterus, and ambiguous genitalia. In case 2, a fetus was diagnosed with a mosaic chromosome composition of 46, XX/47, XXY, and after birth, also displayed one testis, one ovary, a uterus, and ambiguous genitalia. The child in case 1 was adopted from an orphanage and raised as a girl. After consultation with the medical team, the parents decided to continue raising the child as a girl and requested surgery that would completely feminize the child. In case 2, the parents decided to forego treatment and let the child make the choice about gender later in life and to remain neutral about the child’s present condition. These cases raise questions about sex determination and the ethics of sex and gender assignment.

In humans, what is the role of the MSY region of the Y chromosome in sex determination and gender development?