Individuals affected by CAIS develop a normal external female habitus, despite the presence of a Y chromosome, but internally, they will lack a uterus, and the vaginal cavity will be shallow, while the gonads, having been turned into testicles rather than ovaries in the earlier separate process also triggered by their Y chromosome, will remain undescended in the place where the ovaries would have been. This results not only in infertility in individuals with CAIS, but also presents a risk of gonadal cancer later on in life.CAIS is one of the three categories of androgen insensitivity syndrome (AIS) since AIS is differentiated according to the degree of genital masculinization: complete androgen insensitivity syndrome (CAIS) when the external genitalia is that of a typical female, mild androgen insensitivity syndrome (MAIS) when the external genitalia is that of a typical male, and partial androgen insensitivity syndrome (PAIS) when the external genitalia is partially, but not fully masculinized.Androgen insensitivity syndrome is the largest single entity that leads to 46, XY undermasculinization. Signs and symptoms
Physical
Individuals with complete androgen insensitivity syndrome (grades 6 and 7 on the Quigley scale) are born phenotypically female, without any signs of genital masculinization, despite having a 46,XY karyotype. Symptoms of CAIS do not appear until puberty, which may be slightly delayed, but is otherwise normal except for absent menses and diminished or absent secondary terminal hair. Axillary hair (i.e. armpit hair) fails to develop in one third of all cases. External genitalia is normal, although the labia and clitoris are sometimes underdeveloped.
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.