Vaginal depth varies widely for CAIS women, but is typically shorter than unaffected women; one study of eight women with CAIS measured the average vaginal depth to be 5.9 cm  (vs. 11.1 ± 1.0 cm for unaffected women ). In some extreme cases, the vagina has been reported to be aplastic (resembling a "dimple"), though the exact incidence of this is unknown.The gonads in these women are not ovaries, but instead, are testes; during the embryonic stage of development, testes form in an androgen-independent process that occurs due to the influence of the SRY gene on the Y chromosome. They may be located intra-abdominally, at the internal inguinal ring, or may herniate into the labia majora, often leading to the discovery of the condition. Testes in affected women have been found to be atrophic upon gonadectomy.Testosterone produced by the testes cannot be directly used due to the mutant androgen receptor that characterizes CAIS; instead, it is aromatized into estrogen, which effectively feminizes the body and accounts for the normal female phenotype observed in CAIS. However, up to 5% of individuals with CAIS do not have an AR mutation. The receptor in question is encoded by the AR gene located on the X chromosome at Xq11–12. At least 15 different mutations were known in 2003, and they are all recessive, which makes the disease to follow X-linked recessive inheritance.Immature sperm cells in the testes do not mature past an early stage, as sensitivity to androgens is required in order for spermatogenesis to complete.
The incidence of gonadal tumors in childhood is thought to be relatively low; a recent review of the medical literature  found that only three cases of malignant germ cell tumors in prepubescent girls have been reported in association with CAIS in the last 100 years. Some have estimated the incidence of germ cell malignancy to be as low as 0.8% before puberty.Vaginal hypoplasia, a relatively frequent finding in CAIS and some forms of PAIS, is associated with sexual difficulties including vaginal penetration difficulties and dyspareunia.At least one study indicates that individuals with an intersex condition may be more prone to psychological difficulties, due at least in part to parental attitudes and behaviors, and concludes that preventative long-term psychological counseling for parents as well as for affected individuals should be initiated at the time of diagnosis. Lifespan is not thought to be affected by AIS.Despite the well-developed breasts in CAIS women, and for reasons that are not well-understood, breast cancer has never been reported in CAIS women and does not seem to occur or occurs only rarely. Only a case report of juvenile fibroadenoma exists. A few cases of breast cancer have been reported in individuals with partial androgen insensitivity syndrome however. Diagnosis
CAIS can only be diagnosed in normal phenotypic females. It is not usually suspected unless the menses fail to develop at puberty, or an inguinal hernia presents during premenarche.