sex chromosome disorders

Question 1

genetic disorder of a male with an extra X-chromosome (47 XXY)

Answer 1

Klinefelter syndrome

Question 2

testicular atrophy → ↓T → less muscle mass, ↓ facial/body hair, broader hips
tall, long extremities
gynecomastia
female hair distribution
infertilie or reduced fertility
dysgenesis of seminiferous tubules →↓ inhibin →↑FSH

Answer 2

Klinefelter syndrome

Question 3

Barr body present

Answer 3

1 inactivated X chromosome (Barr body) → still have 2 activated X chromosomes in Klinefelter syndrome

Question 4

female with one sex chromosome: 45, XO

Answer 4

Turner syndrome

Question 5

Barr body not present

Answer 5

Turner syndrome

no inactivated X chromsome

Question 6

short stature (

Answer 6

Turner syndrome

may just have 1° amenorrhea and no other obvious features

Question 7

most common cause of 1° amenorrhea

Answer 7

Turner syndrome

Question 8

male with an extra Y chromosome (47 XYY)

Answer 8

double Y males

Question 9

phenotypically normal
tall
severe acne
antisocial behavior (seen in 1-2%)
normal fertility

Answer 9

double Y males