46, XY Sex Reversal (SRXY): Types 1–11

This syndrome was first introduced by Gim Swyer in 1955 with a report of two cases (Swyer 1955). It is classified as a disorder of sex development. Affected individuals are phenotypically normal females with XY karyotypes at birth. They have well-developed Mullerian structures and bilateral streak gonads instead of functional ovaries or testes; therefore, they do not develop secondary sexual characteristics and do not menstruate. People with Swyer syndrome are raised as girls and the diagnosis mainly remains undiscovered until puberty fails to occur. They may be tall with eunuchoid characteristics, normal uterus, and external genitalia. The puberty and sexual development can be induced by hormone replacement therapy at the appropriate age. They have the ability to become pregnant with donated eggs. The exact prevalence of this syndrome remains unclear, but it can be estimated at 1:80,000 births (Michala et al. 2008).