Yes, a woman can have an XXY karyotype. This is a rare condition known as Swyer syndrome, where a person with an XY chromosome makeup develops female external genitalia. This occurs due to a mutation or deletion in the SRY gene located on the Y chromosome, which is responsible for the development of male characteristics. While the individual possesses the Y chromosome, the absence of a functional SRY gene prevents the development of testes, leading to a female phenotype.
Here are some additional points about Swyer syndrome:
- Individuals with Swyer syndrome typically have a female appearance, with normal female genitalia and a uterus.
- They usually have no ovaries, which can lead to infertility.
- They may require hormone replacement therapy to develop secondary sexual characteristics.
- Though rare, a few cases of individuals with Swyer syndrome have been reported to have become pregnant, suggesting that despite the absence of ovaries, the possibility of pregnancy exists.
While Klinefelter syndrome, which involves an extra X chromosome (XXY), typically results in a male phenotype, Swyer syndrome demonstrates that the presence of a Y chromosome alone does not guarantee male development. The functionality of the SRY gene is crucial in determining the sex of an individual.
