Gonadal Dysgenesis is an intersex bodily/corporeal variation of the atypical embryonic development of the gonads, with reproductive tissue replaced with dysfunctional, fibrous tissue, which is called streak gonads. Streak gonads are a form of aplasia, resulting in hormonal failure that manifests as sexual infantism and infertility, with no initiation of puberty and secondary sex characteristics.
One with this variation cannot ovulate as their reproductive tissue is not formed and is instead replaced with simple tissue. This is usually seen with people who have 45,X/46,XY Mosaicism or Turners syndrome, however it can be a variation amongst itself.
This variation may also cause one to fall under the secondary sex agenesis spectrum.
Swyer Syndrome is a form of Gonadal Dysgenesis. It is typically affecting an AFAB otherwise or CTF individual with müllerian genitals and a müllerian reproductive system, that have their functionless gonads that are replaced with streak gonads. If left without HRT, they will not experience puberty. This often causes one to also have AFAB Hypogonadism.
The name was chosen to be named after the endocrinologist who first discovered it, Gerald Swyer.
Swyer syndrome was first described by G. I. M. Swyer in 1955 in a report of two cases.