Androgen Insensitivity Syndrome is also known as androgen resistance syndrome and is a group of disorders associated with sexual differentiation caused by mutations of the gene encoding the androgen receptor. The nature of the problems resulting from this disorder varies depending to a great extent on the sensitivity and structure of the abnormal receptor. Most forms of this disorder involve varying degrees of undervirilization or infertility in XY individuals of any gender. An individual with complete androgen insensitivity syndrome has a female external appearance also known as testicular feminization.

Great advances in the understanding and management of the various forms of androgen sensitivity syndrome have been made since 1990. Patient advocacy groups for individuals affected by this disorder and other intersex conditions have emerged on a large scale in recent years. Also, efforts have been made to increase public awareness about these disorders and have helped revise the understanding of gender identity disorders based on accurate and evidential information for patients. The effectiveness of surgical corrections has also increased and nowadays surgery has become an elective option for the more uncertain conditions.

Problems resulting from Androgen Insensitivity Syndrome:

Although, a number of distinct mutations have been discovered that tend to be the result of androgen sensitivity syndrome, the pathological appearance has been divided into six phenotypes that correspond to the increasing amounts of androgen effect increase in tissue responsiveness.

Complete androgen insensitivity syndrome: In this phenotype, the individual has a complete female body but no uterus, fallopian tubes or ovaries. The testes are present in the abdomen and the individual has minimal androgenic (pubic) hair at puberty.

Partial androgen insensitivity syndrome: In this phenotype, the individual has a female body with slightly virilized genitals and the tested are present in the abdomen. The individual may have sparse or normal pubic hair.

Refenstein syndrome: Here the individual has uncertain genitals, small testes in the abdomen or scrotum and sparse to normal growth of pubic hair.

Infertile male syndrome: In this phenotype, normal male genitals are present both externally and internally with a normal male body with possible female androgyny but reduced sperm production.

Undervirilized fertile male syndrome: In this phenotype, the male genitals are present with a small penis and the sperm count and fertility are normal or reduced.

X-linked spinal and bulbar muscular atrophy: Normal or almost normal male body and adult onset of degenerative muscle disease.