Androgen Insensitivity Syndrome (AIS)
Complete & Partial AIS, the Androgen-Receptor Defect and the 46,XY Phenotype Spectrum
Evidence grade 5 of 5, Settled. Read how the Atlas grades evidence.
The written rationale for this grade is still being prepared.
- FDA
- Not applicable (genetic condition)
Reference only. Not medical advice.
What can go wrong
AIS carries a germ-cell tumor risk from intra-abdominal/inguinal testes (low before puberty in CAIS, higher in some PAIS), requiring individualized decisions about gonadectomy versus surveillance. After gonadectomy, hormone replacement is needed for bone and general health. The condition is also a focal point of the DSD/intersex-ethics debate: historically routine early genital surgery and gonadectomy are now widely criticized, and care should prioritize informed consent, autonomy and multidisciplinary support.
This is something to take to a clinician. The Atlas can tell you what is known about androgen insensitivity syndrome (ais) in general. It cannot tell you what is happening in your body, and the difference matters most for exactly the symptoms that bring people to this page.
Androgen insensitivity syndrome is an X-linked condition in which mutations in the androgen-receptor gene (AR, Xq11-12) cause target tissues to respond poorly or not at all to testosterone and DHT, despite normal or high androgen levels. The phenotype in 46,XY individuals spans a continuum graded on the Quigley scale. In complete AIS (CAIS), external genitalia are typically female and individuals are usually raised female, often presenting with primary amenorrhea or inguinal testes; AMH from functional Sertoli cells regresses the Mullerian ducts, so there is no uterus, and the Wolffian ducts fail to virilize. Partial AIS (PAIS) produces ambiguous genitalia of varying degrees, and mild AIS (MAIS) can present as undervirilization or male infertility. Testes are present and produce testosterone; the defect is downstream at the receptor.
Plenty of testosterone, but the receptor cannot hear it.
What people take it for
What it is taken for. Approval, where it exists, covers only some of these.
How it works
Testosterone and DHT act by binding the androgen receptor, a nuclear transcription factor; the ligand-receptor complex regulates androgen-responsive genes. Loss-of-function AR mutations blunt or abolish this signaling. Because Sertoli-cell AMH is independent of the AR, Mullerian structures still regress in 46,XY AIS (no uterus). In CAIS the Wolffian ducts and external genitalia cannot respond, so internal male ducts are absent/rudimentary and external anatomy is female. At puberty, testosterone is aromatized to estradiol, which acts on intact estrogen receptors, producing breast development and a feminine body habitus in CAIS. Severity tracks how much residual AR function remains.
Gonadal tumor risk and management
The intra-abdominal/inguinal testes in AIS carry a risk of germ-cell tumors (type II GCNIS-derived), though in CAIS the prepubertal risk is low; modern practice often retains gonads through puberty (to allow spontaneous estrogen-driven feminization) with surveillance, individualizing gonadectomy timing, a shift from the older routine of early removal. Management is multidisciplinary and increasingly centers patient autonomy, given that AIS is a paradigm case in the DSD/intersex ethics literature about irreversible early surgery.
What people get wrong
Often saidAIS means low testosterone
ActuallyTestosterone is normal or high; the problem is that the androgen receptor cannot respond to it.
Often saidPeople with CAIS have a uterus that fails to menstruate
ActuallyThere is no uterus, Sertoli-cell AMH regressed the Mullerian ducts, which is why primary amenorrhea is a common presentation.
Who profits, and who pushes back
Intersex advocacy groups
Routine early gonadectomy and 'normalizing' genital surgery in AIS have been heavily criticized; consent and bodily autonomy are now central to guidelines.
What we do not know
- Optimal timing of gonadectomy vs surveillance in CAIS?
- How to standardize shared decision-making around early surgery in PAIS?
At a glance
- Gene
- AR (androgen receptor), Xq11-12
- Inheritance
- X-linked recessive
- Karyotype
- 46,XY
- CAIS external genitalia
- Typically female
- No uterus
- Yes, AMH regresses Mullerian ducts
- Grading
- Quigley scale (1-7)
What this entry does not yet cover
What follows is unfinished work on our side, not a finding about Androgen Insensitivity Syndrome (AIS). A short entry is not a safe entry.
- Timeline. We have not built the dated record of research and regulatory events.
- Cost and market. We have not documented what it sells for or who sells it.
- Supply chain. We have not mapped where it is made.
- Who uses it. We have not documented the user groups.
- What could change. No forward-looking summary yet.
- How it compares. We have not set it against the alternatives.
- Children and teenagers. We have not checked what is known about younger people.
- Where we land. We have not taken a position on this yet.
Sources
The studies below are named and described, but not linked. You cannot open them from here and check our reading against them, which means this page is our summary of the literature rather than a document you can verify. Weigh it accordingly until the links exist.
The studies that matter
Quigley et al., AIS phenotype grading and AR mutations1995
Established the clinical-molecular grading scale and reviewed AR-mutation spectrum
Hughes et al., Lancet, AIS seminar2012
Comprehensive review of pathophysiology, phenotype and management
Chicago Consensus on DSD (Lee et al.)2006
Reframed nomenclature and management of disorders/differences of sex development