Androgen insensitivity syndrome
![Location and structure of the human androgen receptor: Top, the AR gene is located on the proximal long arm of the X chromosome. Middle, the eight exons are separated by introns of various lengths. Bottom, illustration of the AR protein, with primary functional domains labeled (not representative of actual 3-D structure).[3]](/uploads/202502/15/Functional_domains_of_the_human_androgen_receptor.svg0324.png)
![Normal function of the androgen receptor: Testosterone (T) enters the cell and, if 5-alpha-reductase is present, is converted into dihydrotestone (DHT). Upon steroid binding, the androgen receptor (AR) undergoes a conformational change and releases heat shock proteins (hsps). Phosphorylation (P) occurs before or after steroid binding. The AR translocates to the nucleus where dimerization, DNA binding, and the recruitment of coactivators occur. Target genes are transcribed (mRNA) and translated into proteins.[3][13][19][73]](/uploads/202502/15/Human_androgen_receptor_and_androgen_binding.svg0325.png)
Androgen insensitivity syndrome (AIS) is a condition that results in the partial or complete inability of the cell to respond to androgens. The unresponsiveness of the cell to the presence of androgenic hormones can impair or prevent the masculinization of male genitalia in the developing fetus, as well as the development of male secondary sexual characteristics at puberty, but does not significantly impair female genital or sexual development. As such, the insensitivity to androgens is clinically significant only when it occurs in genetic males (i.e. individuals with a Y-chromosome, or more specifically, an SRY gene). Clinical phenotypes in these individuals range from a normal male habitus with mild spermatogenic defect or reduced secondary terminal hair, to a full female habitus, despite the presence of a Y-chromosome.