Genetic Related Developmental Sex Disorders

Question 1

What is aneuploidy?

Answer 1

Unequal distribution of one pair of homologous chromosomes to the daughter cells

Question 2

When does aneuploidy occur?

Answer 2

When daughter sex cells split

Question 3

What is mosaicism?

Answer 3

Nondisjunction during early cleavage of the zygote

Question 4

When does mosaicism occur?

Answer 4

When zygotes split

Question 5

What does every extra X chromosome found in a human cause?

Answer 5

Adds a 15% chance of retardation for each extra X

Question 6

What is a true hermaphrodite?

Answer 6

Has both testes and ovaries in the same body (can be contained in the same structure or separate)

Question 7

What is a pseudohermaphrodite?

Answer 7

Male with testes but wrong external genitalia or female with ovaries but wrong external genitalia

Question 8

What aneuploidy disorders occur in females?

Answer 8

Turner’s Syndrome 45 XO

47 XXX

Question 9

What aneuploidy disorders occur in males?

Answer 9

Klinefelter’s Syndrome 47 XXY

47 XYY

Question 10

What sex genetic mutations occur only in females causing pseudohermaphroditism?

Answer 10

Congenital adrenal hyperplasia

Question 11

What sex genetic mutations occur only in males causing pseudohermaphroditism?

Answer 11

Testosterone insensitivity

5a-reductase deficiency

Question 12

Frequency of Turner’s Syndrome:

Answer 12

1/8000 live female births

Question 13

Intelligence in Turner’s Syndrome?

Answer 13

Normal intelligence

Question 14

What are the key features in Turner’s Syndrome?

Answer 14

Stature below 5 feet
Infertile
Lymph stasis in infants of hand foot and neck
Bilateral webbing of the neck
Complete loss of oocytes by 2 years old
Preductal coarctation (BP high in upper extremity low in lower extremity)

Question 15

What is Klinefelter Syndrome?

Answer 15

47 XXY Male (can be XXXY, XXY, XYY)

Question 16

What is Turner’s syndrome?

Answer 16

45 XO

Question 17

What does a Klinefelter patient present as?

Answer 17

Male with completely female features

Question 18

What is the histology of the testis in Klinefelter patients?

Answer 18

Pink
Hyaline
Collagenous ghosts
Atrophic tubules

Question 19

What happens to seminiferous tubules in Klinefelter?

Answer 19

They do not form leading to decreased inhibin and increased FSH

Question 20

What occurs to sex hormones in Klinefelter?

Answer 20

No Leydig cells to produce Testosterone so GnRH will increase but only effect is an increase in estradiol production

Question 21

Frequency of Klinefelter:

Answer 21

1/660 Male births

Question 22

What occurs in testosterone insensitivity?

Answer 22

Can be one of multiple reasons there is a dysfunction in androgen receptors

Question 23

What is elevated in testosterone insensitivity?

Answer 23

Testosterone and LH

Question 24

What is absent in testosterone insensitivity?

Answer 24

Mesonephric ducts
DHT
Prostate and external genitalia

Question 25

How is testosterone insensitivity differentiated from 17 alpha-hydroxylase deficiency?

Answer 25

Absence of hypertension

Question 26

Why are there no ovaries in testosterone insensitivity?

Answer 26

Because the testis are present therefore are the Sertoli cells to secrete AMH causing destruction of Wolffian ducts

Question 27

Why do testosterone insensitive males have female and not male external genitalia?

Answer 27

No DHT to form male secondary/external genitals

Question 28

Where are testis located in testosterone insensitive females?

Answer 28

In the Labia majora

Question 29

Why do the testis develop in testosterone insensitive females?

Answer 29

There is a Y chromosome to encode for them and not the default ovaries

Question 30

What does 5a-reducatase deficiency cause in males?

Answer 30

No DHT formation from Testosterone

Question 31

What is 5a-reductase deficiency genitalia like?

Answer 31

Testis with female genitalia

Question 32

What is different about 5a-reductase deficiency and testosterone insensitivity?

Answer 32

5a-reductase deficiency you have Wolffian duct since you have AR for testosterone to bind and activate Sertoli cells to release AMH and you develop a rudimentary penis when puberty hits bc the increase in testosterone

Question 33

What can cause female pseudohermaphroditism congenital adrenal hyperplasia?

Answer 33

21a-hydroxylase deficiency | 11b-hydroxylase deficiency

Question 34

Key signs in 21a-hydroxylase deficiency?

Answer 34

Water wasting Hypotension Hyponatremia Hyperkalemia

Question 35

Key signs in 11b-hydroxylase deficiency?

Answer 35

Water retention Edema Hypertension Hypernatremia

Question 36

Why does congenital adrenal hyperplasia occur?

Answer 36

A deficiency in the enzymes forming mineralocorticoids or glucocorticoids will cause a shunting to the formation of androgens causing hyperplasia of the zona reticularis