What are ambiguous genitalia?
Early in fetal development, the tissue that will become the gonads (ovaries or testes) is undifferentiated and has the potential to become either ovaries or testes, depending on the genetics of the fetus. Humans have 46 chromosomes in each cell of their bodies, or 23 pairs. The 23rd pair determines our gender; females have two X chromosomes, while males have one X and one Y chromosome. The chromosome complement in humans is written: 46, XX, normal female or 46, XY, normal male. There is a gene located on the short arm (top half) of the Y chromosome, called “SRY,” which, if present, will cause the undifferentiated gonad to become testes (indicating a male) around the 6th week of fetal life. At the same time, regression of what would have been the female reproductive tract occurs. As the testes produce testosterone, the phallus (penis), scrotum, and urethra form. Later, during the 7th to 8th month of the pregnancy, the testes will descend into the scrotum. In the absence of the SRY gene,