Androgen Insensitivity Syndrome (AIS/TFM) is a disorder of the endocrine glands in individuals with an XY karyotype, characterized by an inability of the body to react to the androgen hormone. Therefore, the individual shows evidence of feminization of the external genitalia at birth, abnormal secondary sexual characteristics at puberty, and infertility.
AIS is inherited in an X-linked recessive fashion. The defective gene in this condition is the Androgen Receptor gene, located on the X chromosome. The gene codes for the Androgen Receptor protein, which is located on cell surfaces, and allows the cells to respond to the androgen hormone, thereby promoting male sexual development and development of secondary sexual characteristics.