"Two adult brothers and a paternal uncle in the U.K. all appear to be normal males — but genetically are women with two X chromosomes."

"Both brothers are married to women, and they and their uncle have the sexual anatomy, behavior, growth, and skeletal development of males. All have normal health and intelligence.... While it's extremely rare for sex reversal to run in a family, it's not unheard of for genetic females to develop as men or for genetic males to develop as women."