Swyer syndrome is sometimes called “XY gonadal dysgenesis” because in this case, a girl is born with 46,XY chromosomes and gonads that did not develop properly. Ordinarily when a fetus has 46,XY chromosomes, the fetus will develop testes and the testes will contribute to male-typical development internally and externally. In Swyer syndrome, the gonads develop into what are called “streak gonads,” so the development is not male typical. In terms of external development, the genitals develop to be female typical. Internally, the fetus develops a uterus, Fallopian tubes, a cervix, and vagina.
Usually streak gonads are surgically removed shortly after diagnosis, because they present a high risk of cancer. Often girls with Swyer syndrome are not diagnosed until they reach the age when they are expected to reach puberty. Girls with Swyer do not undergo a typical female puberty because they lack ovaries, which in typical female development will cause female pubertal development of breasts, wider hips, menstruation, etc.
If a girl with Swyer syndrome is put on hormone replacement therapy, she can undergo a female-typical puberty. Many will menstruate once they are taking replacement female hormones. With in vitro fertilization (IVF) using an egg donated by another woman, a woman with Swyer can carry a pregnancy and give birth to her child vaginally.
The main support group for Swyer syndrome is the AIS-DSD Support Group. For their website, click here
Posted in: Specific Conditions