••• Chapter 53^ Amenorrhea^533
❍ What is the karyotype of a patient with Müllerian agenesis?
46,XX.
❍ In a patient with known Müllerian agenesis, what other system needs to be evaluated and why?
The renal tract because approximately one-third of patients will have urinary tract abnormalities, and the skeletal
system since 12% have skeletal abnormalities including spinal deformities, absent digits, and syndactyly.
❍ Aside from surgical construction of a neovagina, what other method is available?
Vaginal dilators. Eighty percent of women are able to achieve satisfactory intercourse.
❍ What is the diagnosis of a patient with primary amenorrhea, an absent uterus, and little to absent body
hair?
Complete AIS. It is the third most common cause of 1° amenorrhea.
❍ What is the karyotype of a patient with complete androgen insensitivity?
46,XY.
❍ Why are there no uterus, tubes, and upper vagina in AIS?
Anti-Müllerian hormone is present.
❍ How is AIS inherited?
It is an X-linked recessive gene responsible for the intracellular androgen receptor.
❍ Given that patients with AIS have testes and the high incidence of neoplasia if left in situ, when should the
testes be removed?
After puberty (exception to the rule), at approximately 16 to 18 years of age. This is because the development of
secondary sexual characteristics achieved with hormone therapy does not match that with endogenous hormones.
In addition, the incidence of gonadal tumors in these patients is rare before puberty.
❍ Do patients with AIS have normal female levels of testosterone?
No. The levels of testosterone in these phenotypic females are in the normal to slightly elevated male range. Thus,
they produce testosterone but are not able to respond to those androgens.
❍ How can one differentiate a patient with androgen insensitivity from one with 5a-reductase deficiency?
The patient with 5a-reductase deficiency does not develop breasts at puberty. This is due to the levels of
testosterone that are present in sufficient amounts to suppress breast development.
❍ What rare enzyme deficiency causes the same clinical picture as AIS?
17 b-hydroxysteroid dehydrogenase that catalyzes the conversion of androstenedione to testosterone in testicular
Leydig cells.
❍ A very rare cause of amenorrhea in which both male and female gonadal tissue is present is known as what?
True hermaphrodite.