Partial Androgen Insensitivity Syndrome (PAIS)

The extent of androgen insensitivity in 46 XY individuals is quite variable, even in a single family. Partial androgen insensitivity typically results in “ambiguous genitalia.” The clitoris is large or, alternatively, the penis is small and hypospadic (these are two ways of labeling the same anatomical structure). Partial androgen insensitivity may be quite common, and has been suggested as the cause of infertility in many men whose genitals are of typically male appearance.

Individuals with ambiguous genitals have typically been subjected to “corrective” surgery during infancy. Based on our own painful experiences, ISNA believes that such cosmetic surgery of the genitals is harmful and unethical. Surgery is justified only when it is necessary for the health and well-being of the child. Surgery which is intended to make the genitals appear more male or more female should be offered, but not imposed, only when the child is old enough to make an informed decision for her/himself.

Is there a test to find out if you have androgen insensitivity?

The answer depends upon exactly what you are looking for—diagnostic information, or carrier status. If were born with female genitals and testes, and have very sparse or absent pubic hair, you most likely have complete AIS. If you were born with ambiguous genitals and testes, there are a number of possible etiologies, including partial AIS.

Testing for partial AIS is more problematic than the complete form. Hormonal tests in a newborn with 46 XY karyotype and ambiguous genitals will show normal to elevated testosterone and LH, and a normal ratio of testosterone to DHT. A family history of ambiguous genitals in maternal relatives suggests partial androgen insensitivity.

If you are wondering if you are a carrier, or if you know that you are a carrier and are wondering about the status of your fetus, genetic testing is possible. AIS has been diagnosed as early as 9-12 weeks gestation by chorionic villus sampling (sampling tissue from the fetal side of the placenta). By the 16th week it can be detected by ultrasound and amniocentesis. However, prenatal diagnosis is not indicated unless there is a family history of AIS.

See the following for details of testing.

Hodgins M. B., Duke E. M., Ring D.: Carrier detection in the testicular feminization syndrome: deficient 5 alpha-dihydrotestosterone binding in cultured skin fibroblasts from the mothers of patients with complete androgen insensitivity. J. Med. Genet. Jun 1984, 21, (3), p178-81.

Batch J. A., Davies H. R., Evans B. A. J., Hughes I. A., Patterson M. N.: Phenotypic variation and detection of carrier status in the partial androgen insensitivity syndrome. Arch. Dis. Childh. 1993; 68: 453-457.