Androgen insensitivity syndrome (AIS) is a genetic X-linked recessive disorder where affected males have mostly female sex characteristics or signs of both male and female sexual development. Individuals with this condition are genetically male; they contain both an X and Y chromosome (Barbaro et al., 2007). Mutations in the androgen receptor gene are what cause androgen insensitivity syndrome in individuals. This gene produces androgen receptors which are important to males. Without this receptor androgen will not be supplied to the body and that is a major hormone males need. Other names used in place of AIS are as follows; Testicular Feminization Syndrome (TFM), Androgen Receptor Deficiency, Androgen Resistance Syndrome, AR Deficiency, Dihydrotestosterone Receptor Deficiency, and DHTR Deficiency (OMIM, 2012). Androgen insensitivity syndrome can be considered as complete androgen insensitivity syndrome, partial androgen insensitivity syndrome, or mild androgen insensitivity syndrome.
Complete androgen insensitivity syndrome occurs when the body is unable to use androgens at all. Affected individuals with this form have the external sex characteristics of females, but do not have a uterus, will not menstruate, and are infertile. They also will not have axillary or pubic hair, or acne which is linked to puberty. Androgen insensitivity syndrome individuals develop internal male sex organs. Partial androgen insensitivity syndrome (Reifenstein syndrome) is when the body’s tissues are partially sensitive to the effects of androgens. Affected individuals can have normal female sex characteristics, both male and female sex characteristics, or normal male sex characteristics. An individual may be brought up as a male then upon puberty show female characteristics. Affected individuals with mild androgen insensitivity syndrome are born with male sex characteristics, infertile, and have breast enlargement upon puberty (Barbaro et al., 2007). Individuals with androgen insensitivity syndrome have a risk for developing prostate cancer (Kaprova-Pleskacova et al., 2013). Also, patients frequently need medical attention due to a presumed inguinal hernia.
Complete and partial androgen insensitivity syndrome affects 2 to 5 individuals per every 100,000 individuals who are genetically male and mild androgen insensitivity syndrome is much less common compared to the other two forms (Barbaro et al., 2007). Approximately 50% of infants that are born with complete androgen insensitivity syndrome eventually develop a hernia due to the undescended testes. This is the first indication of androgen insensitivity syndrome because at birth no external signs show (Bouvattier et al., 2002).
Overview of Patient Phenotype
Androgen insensitivity syndrome affects sexual development before birth and during puberty. This condition is inherited by an X-linked recessive disorder. It is considered X-linked because the mutation is on the X chromosome. Males only have one...