Androgen Insensitivity Syndrome (AIS) is a genetic condition where people have male chromosomes and male gonads but experience partial or complete feminization of the external genitals. It is caused by mutations in the androgen receptor gene that results in cells not responding properly to androgens like testosterone. People with AIS show a spectrum of physical traits from fully female to ambiguous external genitalia depending on the severity of the mutation. Testing and treatment involves genetic testing, surgery, and hormone replacement therapy, while psychological support is also important.