Distinguish between chromosomal and hormonal disorders of sexual differentiation. Describe in as much detail as you can one disorder of each type.

Question

What will be an ideal response?

Answer 1

Chromosomal disorders occur when the normal pattern of XX or XY is altered in the fetus. This can occur through having an extra chromosome, missing a chromosome, or some other irregularity or damage to the sex chromosomes. Klinefelter's syndrome is the most common form of sex chromosome variation. The fetus will develop as male, but because there is an additional X chromosome, the fetus may show a feminizing effect. This may include narrower shoulders, female hair patterns, and sometimes development of breast tissue. These changes may also be accompanied by learning disabilities, difficulties in social functioning, and fertility problems. Another chromosomal disorder is Turner's syndrome. In this situation, the person has a complete or partial absence of one X chromosome, leaving a chromosome pattern of a single X. Most often raised as female, these individuals are often not diagnosed until puberty, when secondary sex characteristics and the menstrual cycle will be absent; they will most likely also be infertile. Hormonal disorders occur because of irregular exposure to hormones from the fetus's body or the mother's. One example is androgen insensitivity. Due to a mutation in the androgen receptor gene, the fetus's tissues don't respond to testosterone. As a result, the fetus develops the external genitals of a female, although internally it may have incomplete male structures. The child will have an XY chromosomal pattern. Another example is congenital adrenal hyperplasia (CAH). In this case, the adrenal glands do not work properly, producing too much androgen. Children with CAH show rapid growth during childhood, early entrance into puberty, and fertility problems.