Androgen insensitivity syndrome Androgen insensitivity syndrome
(AIS) is when a person who is genetically male (who has one X
and one Y chromosome) is resistant to male hormones (called
androgens). As a result, the person has some or all of the
physical traits of a woman, but the genetic makeup of a man.
Androgen insensitivity syndrome (AIS) is caused by genetic
defects on the X chromosome. These defects make the body unable
to respond to the hormones that produce a male appearance. The
syndrome is divided into two main categories: - Complete AIS -
Incomplete AIS Complete androgen insensitivity prevents the
penis and other male body parts from developing. At birth, the
child looks like a girl. The complete form of the syndrome
occurs in as many as 1 in 20,000 live births. How many male
traits people have differ in incomplete AIS. Incomplete AIS can
include other disorders, such as: - Failure of one or both
testes to descend into the scrotum after birth - Hypospadias, a
condition in which the opening of the ur