ENDOCRINE DISORDERS PART 1 of 1.2 (AB)

Question 1

What is the most common cause of primary hyperparathyroidism?

Answer 1

Parathyroid adenoma

Question 2

What is the classic lab finding triad in primary hyperparathyroidism?

Answer 2

Hypercalcemia, hypophosphatemia, elevated PTH

Question 3

What imaging is used to localize a parathyroid adenoma?

Answer 3

Sestamibi scan

Question 4

What are the bones, stones, groans, and psychiatric overtones in hyperparathyroidism?

Answer 4

Bone pain, kidney stones, abdominal pain, and psychiatric symptoms

Question 5

What is the most common cause of secondary hyperparathyroidism?

Answer 5

Chronic kidney disease

Question 6

Why does chronic kidney disease cause secondary hyperparathyroidism?

Answer 6

Low calcium and high phosphate stimulate PTH release

Question 7

What lab pattern suggests tertiary hyperparathyroidism?

Answer 7

Elevated calcium and very high PTH levels despite correction of renal failure

Question 8

What is the mechanism of tertiary hyperparathyroidism?

Answer 8

Autonomous PTH secretion after long-standing secondary hyperparathyroidism

Question 9

What are the lab findings in hypoparathyroidism?

Answer 9

Low calcium, high phosphate, low PTH

Question 10

What are classic signs of hypocalcemia?

Answer 10

Chvostek’s sign and Trousseau’s sign

Question 11

What is the most common cause of hypoparathyroidism?

Answer 11

Post-surgical removal or damage (e.g., thyroidectomy)

Question 12

What is pseudohypoparathyroidism?

Answer 12

End-organ resistance to PTH

Question 13

What are the lab findings in pseudohypoparathyroidism?

Answer 13

Low calcium, high phosphate, high PTH

Question 14

What physical features are associated with pseudohypoparathyroidism type 1A?

Answer 14

Short stature, round face, short 4th/5th metacarpals

Question 15

At what gestational age is the critical window for gonadal and genitalia formation?

Answer 15

“6-13 weeks AOG.”

Question 16

What does the presence of SRY gene trigger in fetal development?

Answer 16

“It triggers the gonads to differentiate into testes.”

Question 17

What happens to the gonads in the absence of SRY?

Answer 17

“The gonads become ovaries by default.”

Question 18

What is the function of testosterone in male fetal development?

Answer 18

“Testosterone stabilizes and develops the Wolffian ducts into male internal genitalia

Question 19

What is DHT and its role in male fetal development?

Answer 19

“DHT (dihydrotestosterone) is converted from testosterone by 5-alpha reductase and is essential for male external genitalia development

Question 20

What condition results in testicular and penile abnormalities at birth and lack of secondary sex characteristics?

Answer 20

“Klinefelter Syndrome (47XXY) and XX males.”

Question 21

What are the key clinical manifestations of Klinefelter Syndrome?

Answer 21

“Enlarged breasts

Question 22

What laboratory findings are typical for Klinefelter Syndrome?

Answer 22

“Increased gonadotropins (hypergonadotropic)

Question 23

What is the most common cause of testicular failure?

Answer 23

“Klinefelter syndrome (47 XXY).”

Question 24

What is the hallmark feature of Noonan Syndrome?

Answer 24

“Short stature

Question 25

What is the most common treatment for Noonan syndrome patients with growth issues?

Answer 25

"Growth hormone (hGH) therapy."

Question 26

What is the effect of PTPN11 mutations in Noonan syndrome?

Answer 26

"Patients with PTPN11 mutations have poorer growth and are less responsive to hGH treatment."

Question 27

What is Kallman syndrome?

Answer 27

"A form of congenital hypogonadotropic hypogonadism associated with anosmia (loss of smell)."

Question 28

What clinical features are seen in Kallman syndrome?

Answer 28

"Anosmia or hyposmia

Question 29

What is the most common treatment for secondary hypogonadism?

Answer 29

"Testosterone therapy to induce secondary sexual characteristics."

Question 30

What is the role of GnRH pulse therapy in secondary hypogonadism?

Answer 30

"GnRH pulse therapy is used to stimulate the release of LH and FSH in hypothalamic hypogonadotropic hypogonadism."

Question 31

What are the two main types of ovarian hypofunction?

Answer 31

"Primary (hypergonadotropic hypogonadism) and central (hypogonadotropic hypogonadism)."

Question 32

What is the main clinical feature of primary ovarian failure (POF)?

Answer 32

"Loss of normal ovarian function before age 40

Question 33

What are the common causes of primary ovarian failure?

Answer 33

"Turner syndrome (45

Question 34

What is the treatment for Turner syndrome-related ovarian failure?

Answer 34

"Growth hormone therapy and estrogen replacement therapy to induce puberty and support bone health."

Question 35

What is the key feature of central hypogonadotropic hypogonadism?

Answer 35

"Low FSH and LH plus low estrogen due to failure of the hypothalamus or pituitary gland to secrete adequate gonadotropins."

Question 36

What is a common cause of secondary hypogonadism?

Answer 36

"Pituitary tumors

Question 37

What condition is associated with anorexia nervosa and can cause secondary amenorrhea?

Answer 37

"Hypogonadotropic hypogonadism due to malnutrition and weight loss."

Question 38

What is the primary treatment for hypogonadotropic hypogonadism?

Answer 38

"Testosterone therapy to induce secondary sexual characteristics."

Question 39

What is the characteristic feature of McCune-Albright syndrome?

Answer 39

"Precocious gonadarche

Question 40

What is the treatment for GnRH-independent precocious puberty?

Answer 40

"Inhibitors of testosterone synthesis (ketoconazole)

Question 41

What is the definition of primary amenorrhea?

Answer 41

"Failure to start menstruating by age 13 in the absence of secondary sexual characteristics or by age 15 with secondary sexual characteristics present."

Question 42

What are the causes of primary amenorrhea?

Answer 42

"Mayer-Rokitansky-Hauser syndrome

Question 43

What lab findings are typical in primary amenorrhea?

Answer 43

"Increased gonadotropins and decreased sex steroid levels."

Question 44

What is the most common cause of precocious puberty?

Answer 44

"McCune-Albright syndrome."

Question 45

What is central precocious puberty?

Answer 45

"Premature activation of the hypothalamic-pituitary-gonadal axis leading to early development of secondary sexual characteristics."

Question 46

What are the key clinical manifestations of central precocious puberty?

Answer 46

"Early development of secondary sexual characteristics

Question 47

At what gestational age are internal and external genitalia formed?

Answer 47

At 6-13 weeks AOG.

Question 48

What is the bipotential nature of fetal gonads?

Answer 48

Fetal gonads have the potential to develop into either male or female structures depending on genetic and hormonal influences.

Question 49

What are the ducts present in the early embryo?

Answer 49

Both the Mullerian ducts and Wolffian ducts are present.

Question 50

What does the presence of the SRY gene trigger?

Answer 50

It triggers gonads to differentiate into testis.

Question 51

In the absence of SRY, what do the gonads develop into?

Answer 51

The gonads become ovaries by default.

Question 52

What does testosterone from the Leydig cells stabilize and develop?

Answer 52

It stabilizes and develops the Wolffian ducts into male internal genitalia.

Question 53

What is the role of dihydrotestosterone (DHT) in male external genitalia development?

Answer 53

DHT is essential for the formation of the penis and the fission of labioscrotal folds to form the scrotum.

Question 54

What happens in the total absence of androgens?

Answer 54

It leads to female genitalia development.

Question 55

What is the most important estrogen?

Answer 55

Estradiol-17B (E2).

Question 56

How is estrone (E1) related to estrogen?

Answer 56

It is another form of estrogen.

Question 57

What does testosterone to dihydrotestosterone conversion depend on?

Answer 57

It depends on 5-alpha reductase.

Question 58

What is the clinical manifestation of Klinefelter Syndrome (47XXY)?

Answer 58

Enlarged breasts.

Question 59

How is the secondary sex characteristic development affected in XX males?

Answer 59

Secondary sex characteristics will not develop, and testes and penis are abnormally small at birth.

Question 60

What are the laboratory findings in 47XXY Klinefelter Syndrome?

Answer 60

Increased gonadotropins (hypergonadotropic), decreased FSH, LH, and testosterone levels.

Question 61

What is the clinical manifestation of Noonan syndrome?

Answer 61

Short stature, webbing of the neck, pectus carinatum or excavatum, cubitus valgus, right-sided CHD, and cryptorchidism.

Question 62

How does growth hormone (hGH) treatment affect Noonan syndrome patients?

Answer 62

hGH improves growth velocity, with an average increase in height of 9.5-13 cm for boys and 9.0-9.8 cm for girls.

Question 63

Which mutation affects growth in Noonan syndrome?

Answer 63

PTPN11 mutations.

Question 64

What does a mutation in PTPN11 cause in Noonan syndrome patients?

Answer 64

It leads to poor growth and lower insulin-like growth factor-1 (IGF-1) levels.

Question 65

Which syndrome is associated with anosmia and congenital hypogonadotropic hypogonadism?

Answer 65

Kallman syndrome.

Question 66

What does GnRH pulse therapy treat?

Answer 66

It treats hypothalamic hypogonadotropic hypogonadism (HH).

Question 67

What is the treatment for secondary hypogonadism to induce secondary sexual characteristics?

Answer 67

Testosterone therapy.

Question 68

What is a recommended treatment for patients with Noonan syndrome who are below the 3rd percentile for height?

Answer 68

hGH treatment is recommended.

Question 69

How does GnRH pulse therapy restore gonadotropin secretion?

Answer 69

It restores gonadotropin secretion by using pulsatile administration.

Question 70

What is primary ovarian insufficiency (POI)?

Answer 70

POI is defined as the loss of normal ovarian function before age 40, leading to menstrual irregularity, infertility, and hypoestrogenism.

Question 71

What causes primary ovarian insufficiency in Turner syndrome?

Answer 71

Ovarian dysgenesis, where one X chromosome is missing or partially missing.

Question 72

Which features characterize Turner syndrome?

Answer 72

Short stature, sexual infantilism, webbed neck, cubitus valgus, and cardiac defects.

Question 73

How is estrogen replacement therapy used in Turner syndrome?

Answer 73

Estrogen replacement therapy is used to induce puberty and support bone health.

Question 74

What causes central hypogonadism?

Answer 74

Central hypogonadism is due to a failure in the hypothalamus or pituitary to secrete adequate gonadotropins.

Question 75

What is the common cause of testicular failure in Klinefelter syndrome?

Answer 75

Klinefelter syndrome (47 XXY) is the most common cause of testicular failure.

Question 76

What condition is associated with delayed puberty and low gonadotropins in both males and females?

Answer 76

Kallman syndrome.

Question 77

What is the main cause of sexual precocity in McCune-Albright syndrome?

Answer 77

The main cause is precocious gonadarche due to a mutation in GNAS.

Question 78

What is the treatment for peripheral precocious puberty?

Answer 78

Testosterone synthesis inhibitors like ketoconazole and antiandrogens like spironolactone.

Question 79

What is the role of hCG-secreting tumors in precocious puberty?

Answer 79

hCG-secreting tumors cause testosterone production and virilization in males by activating LHCG receptors in Leydig cells.

Question 80

How does the diagnosis of primary amenorrhea differentiate from hypogonadotropic hypogonadism?

Answer 80

Primary amenorrhea is characterized by normal gonadotropin levels with absent or low sex steroids, whereas hypogonadotropic hypogonadism has low gonadotropin levels.

Question 81

What are the main features of central precocious puberty?

Answer 81

Central precocious puberty involves premature activation of the hypothalamic-pituitary-gonadal axis, with normal endocrine and physical puberty but occurring too early.

Question 82

What differentiates central from peripheral precocious puberty?

Answer 82

Central precocious puberty involves the HPG axis, while peripheral does not.