Mehl. + UW Tuner syndrome 04-15 (1)

Question 1

Mehl. What karyotype is associated with a female phenotype in Turner syndrome?

Answer 1

45XO karyotype

This indicates the presence of a single X chromosome and no second sex chromosome.

Question 2

Mehl. What is NOT visible on electron microscopy in a 45XO karyotype?

Answer 2

Barr body (Q can say that)

A Barr body is an inactivated X chromosome; in this case, it is absent due to the single X chromosome.

Question 3

Mehl. What causes infertility in individuals with Turner syndrome?

Answer 3

Streak ovaries

Streak ovaries are non-functional ovaries that do not produce eggs.

Question 4

Mehl. Infertile due to streak ovaries. In Turner, this is colloquially referred to as “menopause before menarche.”

Answer 4

.

This term highlights the premature ovarian failure experienced in Turner syndrome.

Question 5

Mehl. can have kids through what method?

Answer 5

IVF

Question 6

Mehl. Can still have children with IVF using donor egg + exogenous hormones (asked sometimes on behavioral/psych Qs).

Answer 6

.

Question 7

Mehl. LH and FSH levels?

Answer 7

LH and FSH both ­incr. due to primary hypogonadism.

(i.e., ̄ negative-feedback at hypothalamus and anterior pituitary due to ̄ ovarian hormones and inhibin).

Question 8

Mehl. stature?

Answer 8

Short stature (usually < 5 feet)

Question 9

Mehl. breast tanner?

Answer 9

Tanner stage 1 breast development (“shield chest”),

Question 10

Mehl. pubic hair tanner?

Answer 10

normal pubic and axillary hair (Tanner 4-5).

Question 11

Mehl. finding in neck?

Answer 11

cystic hygroma (webbed neck due to lymphatic insufficiency; asked on NBME);

Question 12

Mehl. Seen scattered nevi (confuses students for things like NF1, but I don’t know what to say; you need to know scattered nevi are seen in Turner);

Question 13

Mehl. incr. risk for what? reproductive

Answer 13

Incr.­ risk of dysgerminoma developing from the streak ovaries;

Question 14

Mehl. what is recommended to prevent dysgerminoma from streak ovaries?

Answer 14

prophylactic oophorectomy is recommended, especially if there is Y-chromosome material present in rarer mosaic forms of Turner

Question 15

Mehl. If Q tells you there’s a fraction of a female’s cells that are 46XX and another fraction that’s 45XO (i.e., somatic mosaic Turner), the answer for the mechanism is?????

Answer 15

“post-fertilization mitotic error.”

Question 16

Mehl. HY cardiac pathologies?2

Answer 16

Coarctation of the aorta + bicuspid aortic valve (aortic stenosis) HY.

Question 17

UW. etiology?

Answer 17

Complete or partial loss of X chromosome

Question 18

UW. CP in infancy? 2

Answer 18

Lymphedema, cystic hygroma

Renal and heart defects (horsehoe kidney, aortic coarctation, bicuspid aortic valve)

Question 19

UW. CP in childhood? 2

Answer 19

Short stature

Dysmorphic features: webbed neck, broad chest, high-arched palate, cubitus vagus, short 4th metacarpal

Question 20

UW. CP in adolescnece? 2

Answer 20

Delayed tenarche

Amenorrhea (primary or secondary)

Question 21

UW. Dx?2

Answer 21

Karyotype (45X)
Comorbidity screenin (cardiac and renal imaging)

Question 22

UW. Tx?

Answer 22

groth hormone and estrogen (+/- progestin) therapy

Question 23

UW. definition of short stature?

Answer 23

height ≥2 standard deviations below the mean or ≤2nd percentile for age.

Question 24

UW. why patients have short stature?

Answer 24

SHOX (short stature homeobox) gene is contained on the X chromosome

Question 25

UW. why gonadal insuf.?

Answer 25

Gonadal insufficiency is due to replacement of ovarian follicles by connective tissue ("streak ovaries") and becomes apparent in adolescence (eg, absent breast development, primary amenorrhea).

Question 26

UW. treatment is recombinant growth hormone when height falls <5th percentile to maximize linear growth potential.

Answer 26

.

Question 27

UW. kitas variantas: Estradiol therapy is initiated around age 11 to induce puberty and breast development and reduce the risk for osteoporosis and associated cardiovascular complications

Answer 27

After menarche, progestin is typically added to mitigate endometrial hyperplasia risk.