Genetic Disorders - Sex Chromosome Disorders

Question 1

Which is more common - sex chromosome or autosome disorders?

Answer 1

Sex chromosome - more tolerated

Question 2

2 factors of sex chromosome disorders?

Answer 2

1. Lyonization of all but 1 x chromosome

2. Modest amount of genetic material carried by Y chromosome

Question 3

What is the Lyon Hypothesis?

Answer 3

Only 1 X chromosome is active!

Question 4

With the Lyon Hypothesis, when are the rest of the X chromosomes inactivated?

Answer 4

5th day gestation

Question 5

How is one X chromosome inactivated?

Answer 5

Heteropyknosis

Question 6

Normal females are mosaics which means?

Answer 6

1 set of cells with inactivated maternal X

1 set of cells with inactivated paternal X

Question 7

What is the inactive X called morphologically?

Answer 7

Barr body

Question 8

Barr body

Answer 8

Inactive X

- small mass in contact with nuclear membrane

Question 9

Small mass in contact with nuclear membrane is probably?

Answer 9

Barr body

- Inactive X

Question 10

Can some genes escape X inactivation?

Answer 10

Yes

Question 11

Presence of a Y chromosome =

Answer 11

Male

Question 12

If there is increased number X chromosomes, what will increase?

Answer 12

Intellectual disability

Question 13

Severe intellectual disability correlates with more?

Answer 13

X chromosomes

Question 14

Hermaphrodite

Answer 14

Presence of BOTH testicular tissue and ovarian tissue

Question 15

Presence of BOTH testicular tissue and ovarian tissue

Answer 15

Hermaphrodite

Question 16

Female Pseudohermaphrodite

Answer 16

Ovarian tissue with male external genitalia

Question 17

Male Pseudohermaphrodite

Answer 17

Testicular tissue with female external genitalia

Question 18

Klinefelter

Answer 18

47 XXY

Question 19

47 XXY

Answer 19

Klinefelter

Question 20

Most common cause of male hypogonadism?

Answer 20

Klinefelter

Question 21

When does hypogonadism usually get diagnosed?

Answer 21

After puberty

Question 22

Symptoms of Klinefelter

Answer 22

Long legs, small testes and small penis, gynecomastia, Low IQ, lack male characterisitics

Question 23

Klinefelter men lack?

Answer 23

Male characteristics

Question 24

Long legs, small testes and small penis, gynecomastia

Answer 24

Klinefelter

Question 25

What metabolic and bone diseases are those with Klinefelter more at risk of developing?

Answer 25

Type 2 DM and metabolic syndrome

Osteoporosis

Question 26

What type of tumors/cancers are those with Klinefelter more at risk of developing?

Answer 26

Teratomas, breast cancer

– Extragonadal germ cell tumors

Question 27

Which sex chromosomal disorder is at risk of developing SLE?

Answer 27

Klinefelter

Question 28

Turner Syndrome

Answer 28

45 X

Question 29

45 X

Answer 29

Turner Syndrome

Question 30

Most common sex chromosomal abnormality in females?

Answer 30

Turner Syndrome

Question 31

If Turner syndrome patients have some Y chromosome sequences, what are they are risk for developing?

Answer 31

Gonadoblastoma

Question 32

Physical finding of those with Turner Syndrome at birth?

Answer 32

Cystic hygroma

= edema swelling at neck

Question 33

With Turner syndrome, what does the cystic hygroma turn into?

Answer 33

Bilateral neck webbing

Question 34

Symptoms of Turner Syndrome?

Answer 34

Bilateral neck webbing, short stature, amenorrhea, streak ovaries

Question 35

Bilateral neck webbing, short stature, amenorrhea, streak ovaries

Answer 35

Turner Syndrome

Question 36

What are streak ovaries?

Answer 36

Fibrotic ovaries seen with Turner syndrome

Question 37

What cardiovascular abnormalities are common in Turner Syndrome?

Answer 37

Coarctation of aorta

Bicuspid aortic valve