Click here to view. Androgen insensitivity syndrome is the most studied of the disorders of sexual differentiation testicular feminization syndrome, androgen insensitivity syndrome. The androgen receptor in this condition is either absent or unable to bind androgen or transduce the androgenic signal to target genes. 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 adult patients, serum testosterone levels are in the male range or higher, serum LH is normal or elevated, and serum estradiol levels are between the normal male and female ranges. These assays are Because of the fact that the androgen receptor is on the X chromosome, CAIS is an X-linked disorder. 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. Mutations in the gene encoding AR may consist of complete absence, large deletions, or point mutations introducing premature stop codons that cause complete disruption of the protein sequence.