XY women with androgen insensitivity syndrome are phenotypically female, with female external genitalia, a short blind-ending vagina, and The diagnosis frequently is made in infancy or childhood because most girls with CAIS have bilateral inguinal hernias containing testes. Alternatively, the girl may seek help in adolescence when menstruation does not occur despite normal breast development. Pubic hair is either completely absent or very sparse. In most cases, a mutation in the coding region of the gene for the AR can be demonstrated, and extensive structure-function studies have been carried out. Similar to all steroid receptors, the AR is a ligand-dependent transcription factor.
Patients can be normal males or somewhat eunuchoid with gynecomastia.
Mullerian structures are absent. If an infant has a phallus that is intermediate in size between a normal penis and a normal clitoris, an aberrantly located urethral opening, and at least one impalpable gonad, the term ambiguous genitalia may be used. The degree of external ambiguity is variable. When the gonads in one individual are comprised of both ovarian and testicular elements, the condition is called true hermaphroditism. The most common gonad found is an ovotestis, and gonads with purely ovarian tissue are more likely to be found on the left side.