Disorders of Sexual Development

Question 1

What is the karyotype of a patient with Klinefelter syndrome?

Answer 1

47,XXY

Question 2

Detail the body habitus of a male with Klinefelter syndrome.

Answer 2

Testicular atrophy
Tall
Long extremities
Gynecomastia
Female hair distribution

Question 3

What are the LH and FSH levels of a patient with Klinefelter syndrome?

Answer 3

Increased- lack inhibin and testosterone

Question 4

What is the karyotype of a patient with Turner syndrome.

Answer 4

45,XO

Question 5

Detail common clinical findings associated with Turner syndrome.

Answer 5

Shield chest
Webbed neck (lymphatic defects)
Bicuspid aortic calve 
Preductal coarctation (femoral pulse is less than brachial pulse)
Horseshoe kidney

Question 6

What is the most common cause of primary amenorrhea?

Answer 6

Turner syndrome

Question 7

What are the LH and FSH levels of a patient with Turner syndrome?

Answer 7

Increased- decreased estrogen

Question 8

Detail the sexual development of an individual with androgen insensitivity syndrome.

Answer 8

Female external genitalia with a short vagina
Absence of Mullerian structures (due to production of AMH from testes)
Lack of Wolffian structures

Question 9

Detail the lab findings for T/LH in a patient with androgen insensitivity syndrome.

Answer 9

High T

High LH

Question 10

Detail the lab findings for T/LH in a patient with a testosterone secreting tumor or exogenous steroid use.

Answer 10

High T

Low LH

Question 11

Detail the lab findings for T/LH in a patient with primary hypogonadism.

Answer 11

Low T

High LH

Question 12

Detail the lab findings for T/LH in a patient with hypogonadotropic hypogonadism.

Answer 12

Low T

Low LH

Question 13

Detail the phenotype of a 46XX female with aromatase deficiency.

Answer 13

Masculinization of infants (ambiguous genitalia)

Mother may present with virilization (fetal androgens cross the placenta)

Question 14

Do patients with androgen insensitivity have testes?

Answer 14

Yes, must be removed to prevent malignancy

Question 15

What is Kallmann syndrome?

Answer 15

Form of hypogonadotrophic hypogonadism
Results from defective migration of GnRH cells and formation of olfactory bulb
Low sperm counts in males
Amenorrhea in females

Question 16

What is the most common DSD in a 46XX fetus?

Answer 16

21-hydroxylase deficiency

Question 17

Detail the presentation of a XX patient with 21-hydroxylase deficiency.

Answer 17

Salt wasting (infant)
Precocious puberty (childhood)
Virilization
(note, presentation depends on degree of enzyme deficiency)

Question 18

What CAH causes salt retention?

Answer 18

17α-hydroxylase

11β-hydroxylase

Question 19

What is the phenotype of a 46XX patient with 11β-hydroxylase deficiency?

Answer 19

Virilization

Question 20

What is the phenotype of a 46XY patient with 17α-hydroxylase deficiency?

Answer 20

Ambiguous genitalia

Undescended testes

Question 21

What is the phenotype of a 46XX patient with 17α-hydroxylase deficiency?

Answer 21

Present with lack of secondary sexual characteristics at puberty

Question 22

All CAH are characterized by what change in the adrenal glands?

Answer 22

Enlargement- increased ACTH due to lack of cortisol

Question 23

Contrast gonadarche and adrenarche.

Answer 23

Gonadarche- re-emergence of hypothalamic GnRH secretion which stimulates gonadotropes to secrete FSH and LH
Adrenarche- maturation of adrenal gland and production of adrenal androgens

Question 24

What is the first physical sign of puberty in boys and girls?

Answer 24

Boys- testicular enlargement

Girls- breast bud development

Question 25

What is the normal age on onset of puberty in boys?

Answer 25

9-14

Question 26

What is the normal age of onset of puberty in girls?

Answer 26

Caucasian- 8-13 | African-American/Hispanics- 1 year earlier

Question 27

Delayed puberty is defined as the lack of onset or lack of normal progression of puberty. What physical findings in boys is associated with delayed puberty?

Answer 27

No testicular enlargement by age 14

Question 28

Delayed puberty is defined as the lack of onset or lack of normal progression of puberty. What physical findings in girls is associated with delayed puberty?

Answer 28

No breast development by age 13 No menses 4 years after pubertal onset No menses by age 16

Question 29

The approach to delayed puberty is to categorize based on gonadotropin status. Elevated gonadotropins (hypergonadotropic hypogonadism) indicate primary gonadal failure, and low gonadotropins (hypogonadotropic hypogonadism) indicate hypothalamic or pituitary immaturity or dysfunction. What is the most common cause of delayed puberty associated with low gonadotropins?

Answer 29

Constitutional growth delay (late bloomers)

Question 30

When can the diagnosis of precocious puberty be made?

Answer 30

When puberty begins before defined lower age limits

Question 31

Complete precocious puberty is defined by early onset, and progression, of pubertal development. What can happen in children with regards to their height in this situation?

Answer 31

Growth plates can close early- short stature

Question 32

Precocious puberty occurs more commonly in girls but the majority of affected girls will have no identifiable abnormality (idiopathic). The prevalence of precocious puberty in boys is significantly lower, but 50% of affected boys will have what type of lesion?

Answer 32

CNS lesion- central precocious puberty

Question 33

What test can be ordered to distinguish between central and peripheral precocious puberty?

Answer 33

GnRH stimulation test Pubertal response = central Prepubertal response = peripheral

Question 34

How can central precocious puberty be treated?

Answer 34

GnRH analog (leuprolide)