Reifenstein syndrome (partial androgen insensitivity) is an inherited condition caused by a mutation of the androgen receptor gene in which testes are present but both male and female sexual characteristics exist. In approximately two thirds of the cases, the syndrome is inherited from the mother; in the other third, a mutation occurs. Outward genitalia can range from female (Grade 7), to mixed male and female, to male (Grade 1). Although they possess the chromosomal makeup of males, babies with Reifenstein syndrome may be raised as either males or females, depending on the severity of the syndrome. The approximate prevalence is approximately 1 in every 20,000 births. Symptoms of Reifenstein syndrome include sterility, a lack of testosterone, breast development, and the failure of one or both testes to descend into the scrotum. Reifenstein syndrome is present at birth. Other names for Reifenstein syndrome include androgen resistance syndrome, feminizing testes syndrome, – Gilbert-Dreyfus syndrome, Goldberg-Maxwell syndrome, incomplete testicular feminization, Lubs syndrome, male pseudohermaphroditism, Morris’s syndrome, Rosewater syndrome, testicular feminization syndrome, and Type I familial incomplete male pseudohermaphroditism. A more severe form of Reifenstein syndrome is complete androgen insensitivity.