Androgen Insensitivity Syndrome What Is Androgen Insensitivity Syndrome? Androgen insensitivity syndrome (AIS) is a rare condition that affects sexual development. It occurs when someone is genetically male, but their body doesn’t respond to male sex hormones called androgens. This results in a person having male sex chromosomes (one X and one Y chromosome) but not having male genitals. AIS affects males during fetal development and during puberty. AIS was previously called testicular feminization syndrome. AIS happens due to genetic mutations, which are changes to genes that affect how they function. With AIS, the gene mutation prevents male genitals from developing in people who are genetically male. AIS almost always results in infertility. Receiving an AIS diagnosis for yourself or your child can be difficult. The condition isn’t life-threatening, but people with AIS may struggle with gender identity or have concerns about their body image. It’s helpful to have a supportive network...