What happens when a person has Swyer syndrome?
Girls with Swyer syndrome lack sex glands (ovaries). Instead of sex glands, women with Swyer syndrome have “gonadal streaks”, in which the ovaries do not develop properly (aplasia) and are replaced by functionless scar (fibrous) tissue.
What gene causes Swyer syndrome?
Because the SRY gene is on the Y chromosome, Swyer syndrome caused by SRY gene variants is described as having a Y-linked inheritance pattern . When Swyer syndrome is associated with an MAP3K1 or NR5A1 gene variant, the condition is also often caused by a new variant that is not inherited.
What gender is Swyer syndrome?
People with Swyer syndrome have female external genitalia and some female internal reproductive structures. These individuals usually have a uterus and fallopian tubes, but their gonads (ovaries or testes) are not functional. Instead, the gonads are small and underdeveloped and contain little gonadal tissue.
What hormone is elevated in gonadal dysgenesis?
| Gonadal dysgenesis | |
|---|---|
| Specialty | Medical genetics |
| Diagnostic method | pelvic examination (checking for maturation of external internal genitals), general examination (looking for secondary sexual characters), chromosome karyotyping, hormone levels like FSH, LH (which are increased in case of purely XX dysgenesis) |
Will a patient with Swyer syndrome have pubic hair?
Swyer syndrome patients are normal-to-tall, present with small or undeveloped breasts, with normal axillary and pubic hair development. The external genitalia are typical of females. Upper part of the vagina and tubes are normal or reduced, and the uterus is small or rudimentary.
What is XY gonadal dysgenesis?
XY gonadal dysgenesis (GD) is a result of abnormal testis development in utero. There are three types of GD, pure (or complete), partial, or mixed, all of which can be differentiated by the extent of normal testicular tissue within the gonad and karyotype of the individual.
What causes gonadal dysgenesis?
Pure 46, XX gonadal dysgenesis is typically caused by alterations to genetic information needed for ovarian development, present at the proximal Xp, and distal Xq regions of the X chromosome. These alterations include gene translocations, deletions, and mutations.