Growth/Development US Medical PG Practice Questions and MCQs
Practice US Medical PG questions for Growth/Development. These multiple choice questions (MCQs) cover important concepts and help you prepare for your exams.
Growth/Development US Medical PG Question 1: A 45 year-old gentleman presents to his primary care physician complaining of wrist pain and is diagnosed with carpal tunnel syndrome. Upon further questioning, the patient admits that he has recently been outgrowing his gloves and shoes and has had to purchase a new hat as well due to increased head size. Upon exam, he is found to have new mild hypertension and on basic labs he is found to be hyperglycemic. Which of the following is the best blood test to diagnose his suspected disorder?
- A. Hydroxyproline level
- B. Cortisol level
- C. Alkaline Phosphatase level
- D. IGF-1 level (Correct Answer)
- E. Growth Hormone level
Growth/Development Explanation: ***IGF-1 level***
- The patient's symptoms of increased glove, shoe, and hat size, along with carpal tunnel syndrome, hypertension, and hyperglycemia, are highly suggestive of **acromegaly**.
- **IGF-1 (Insulin-like Growth Factor 1)** levels are generally stable throughout the day and are directly correlated with average growth hormone (GH) levels, making it the **best initial screening test** for acromegaly.
*Growth Hormone level*
- While acromegaly is caused by **excess growth hormone**, a single random GH level can be misleading due to its **pulsatile secretion**.
- A more definitive diagnostic test for acromegaly involves a **glucose suppression test** by measuring GH levels after an oral glucose load, but IGF-1 is the preferred initial screening.
*Hydroxyproline level*
- **Hydroxyproline** is an amino acid primarily found in **collagen** and its urinary excretion can indicate collagen turnover.
- It is not a primary diagnostic marker for acromegaly and is more relevant in conditions involving bone metabolism or collagen degradation.
*Cortisol level*
- **Cortisol** is a steroid hormone associated with stress response and conditions like **Cushing's syndrome** or **Addison's disease**.
- While acromegaly can sometimes coexist with other pituitary disorders, cortisol levels are not the most appropriate initial test for the suspected diagnosis of acromegaly.
*Alkaline Phosphatase level*
- **Alkaline phosphatase (ALP)** is an enzyme found in various tissues, including bone, liver, and kidneys.
- Elevated ALP typically indicates **bone turnover** (e.g., Paget's disease, osteomalacia) or liver disease, and is not a specific diagnostic marker for acromegaly.
Growth/Development US Medical PG Question 2: A 15-year-old girl comes to the physician with her father for evaluation of her tall stature. She is concerned because she is taller than all of her friends. Her birth weight and height were within normal limits. Her father is 174 cm (5 ft 7 in) tall; her mother is 162 cm (5 ft 3 in) tall. She is at the 98th percentile for height and 90th percentile for BMI. She has not had her menstrual period yet. Her mother has Graves disease. Vital signs are within normal limits. Examination shows a tall stature with broad hands and feet. There is frontal bossing and protrusion of the mandible. Finger perimetry is normal. The remainder of the examinations shows no abnormalities. Serum studies show a fasting serum glucose of 144 mg/dL. An x-ray of the left hand and wrist shows a bone age of 15 years. Which of the following is the most appropriate definitive treatment for this patient's condition?
- A. Caloric restriction
- B. Letrozole therapy
- C. Methimazole therapy
- D. Transsphenoidal adenomectomy (Correct Answer)
- E. Leuprolide therapy
Growth/Development Explanation: ***Transsphenoidal adenomectomy***
- The patient's clinical presentation, including **tall stature with broad hands and feet**, frontal bossing, mandibular prognathism, primary amenorrhea, and elevated fasting glucose, is highly suggestive of **gigantism** (growth hormone excess before epiphyseal closure) due to a **GH-secreting pituitary adenoma**.
- **Transsphenoidal adenomectomy** is the **definitive treatment** to surgically remove the GH-secreting tumor, thereby normalizing GH levels and preventing further progression of gigantism.
- This is the most appropriate treatment to address the **underlying cause** and halt disease progression.
*Caloric restriction*
- While caloric restriction might impact overall growth, it is not a treatment for a hormonally driven condition like **gigantism** caused by a pituitary adenoma.
- It would not address the underlying **excess growth hormone production** or prevent the associated physical changes and metabolic complications.
*Letrozole therapy*
- **Letrozole** is an **aromatase inhibitor** used primarily in the treatment of estrogen-dependent breast cancer and sometimes to induce ovulation or delay puberty in tall stature from other causes.
- It does not directly target or reduce **growth hormone secretion** from a pituitary adenoma and is not appropriate for treating gigantism.
*Methimazole therapy*
- **Methimazole** is an **antithyroid medication** used to treat hyperthyroidism by reducing thyroid hormone production.
- While the patient's mother has Graves' disease, this patient's symptoms are not indicative of thyroid dysfunction, and methimazole would not treat **GH excess** from a pituitary adenoma.
*Leuprolide therapy*
- **Leuprolide** is a **GnRH agonist** used to suppress puberty (e.g., in central precocious puberty) or for hormone-sensitive cancers.
- It primarily affects the **hypothalamic-pituitary-gonadal axis** and has no direct role in treating **growth hormone excess** from a pituitary adenoma.
Growth/Development US Medical PG Question 3: A 15-year-old girl comes to the physician with her father for evaluation of short stature. She feels well overall but is concerned because all of her friends are taller than her. Her birth weight was normal. Menarche has not yet occurred. Her father says he also had short stature and late puberty. The girl is at the 5th percentile for height and 35th percentile for weight. Breast development is Tanner stage 2. Pubic and axillary hair is absent. An x-ray of the left hand and wrist shows a bone age of 12 years. Further evaluation of this patient is most likely to show which of the following sets of laboratory findings?
- A. High FSH, High LH, Normal Estradiol, Normal Prolactin
- B. Normal FSH, Normal LH, Normal Estradiol, Normal Prolactin
- C. Normal FSH, Normal LH, Low Estradiol, Normal Prolactin
- D. Low-normal FSH, Low-normal LH, Low Estradiol, Normal Prolactin (Correct Answer)
- E. Low FSH, Low LH, Low Estradiol, Normal Prolactin
Growth/Development Explanation: ***Low-normal FSH, Low-normal LH, Low Estradiol, Normal Prolactin***
- This pattern is characteristic of **constitutional delay of growth and puberty (CDGP)**, where the hypothalamic-pituitary-gonadal (HPG) axis has not yet fully matured, resulting in low-normal gonadotropins and low estradiol.
- The key clinical features supporting CDGP include: **delayed bone age** (12 years vs chronologic age 15), **positive family history** of late puberty, normal growth velocity, and absence of pathological findings.
- In CDGP, gonadotropins are in the **low-normal or prepubertal range** but will eventually rise spontaneously as the HPG axis matures, distinguishing this from permanent hypogonadotropic hypogonadism.
- GnRH stimulation testing would show a pubertal (not prepubertal) response, confirming the functional delay rather than a pathologic deficiency.
*Low FSH, Low LH, Low Estradiol, Normal Prolactin*
- This pattern suggests **hypogonadotropic hypogonadism**, such as Kallmann syndrome or functional hypothalamic amenorrhea, where gonadotropins are frankly low (not just low-normal).
- While this also presents with low estradiol and delayed puberty, patients with hypogonadotropic hypogonadism typically lack the **positive family history** and would not show delayed bone age suggesting growth potential.
- The distinction is that in permanent hypogonadotropic hypogonadism, the HPG axis is deficient and will not mature spontaneously without hormonal treatment.
*High FSH, High LH, Normal Estradiol, Normal Prolactin*
- This combination is inconsistent with delayed puberty, as high gonadotropins indicate **hypergonadotropic hypogonadism** (primary ovarian failure such as Turner syndrome).
- Hypergonadotropic hypogonadism presents with **high FSH/LH and low estradiol** (not normal), as the pituitary attempts to stimulate non-responsive ovaries.
- This patient's delayed bone age and family history make a physiologic delay (CDGP) much more likely than ovarian failure.
*Normal FSH, Normal LH, Normal Estradiol, Normal Prolactin*
- **Normal estradiol** at age 15 would indicate that puberty is progressing appropriately, which contradicts this patient's clinical presentation.
- The patient has delayed menarche, absent pubic/axillary hair, only Tanner stage 2 breast development, and bone age of 12 years - all indicating **low estradiol** and delayed pubertal progression.
- If all hormones were normal, we would expect more advanced pubertal development at this age.
*Normal FSH, Normal LH, Low Estradiol, Normal Prolactin*
- While low estradiol correctly reflects delayed puberty, describing FSH and LH as fully "normal" is imprecise for CDGP.
- In CDGP, gonadotropins are characteristically in the **low-normal or prepubertal range**, not at robust normal adult levels, reflecting the immature but eventually functional HPG axis.
- The distinction between "normal" and "low-normal" gonadotropins is clinically important for differentiating constitutional delay from other causes of delayed puberty.
Growth/Development US Medical PG Question 4: A 4-year-old boy is brought to the pediatrician by his mother for a routine medical examination. His medical history is relevant for delayed gross motor milestones. The mother is concerned about a growth delay because both of his brothers were twice his size at this age. Physical examination reveals a well-groomed and healthy boy with a prominent forehead and short stature, in addition to shortened upper and lower extremities with a normal vertebral column. The patient’s vitals reveal: temperature 36.5°C (97.6°F); pulse 60/min; and respiratory rate 17/min and a normal intelligence quotient (IQ). A mutation in which of the following genes is the most likely cause underlying the patient’s condition?
- A. Runt-related transcription factor 2
- B. Alpha-1 type I collagen
- C. Fibroblast growth factor receptor 3 (Correct Answer)
- D. Insulin-like growth factor 1 receptor
- E. Fibrillin-1
Growth/Development Explanation: ***Fibroblast growth factor receptor 3***
- The constellation of **short stature**, prominent forehead, and **shortened upper and lower extremities** with a normal vertebral column in a child with normal intelligence is characteristic of **achondroplasia**.
- Achondroplasia is caused by a gain-of-function mutation in the **fibroblast growth factor receptor 3 (FGFR3)** gene, which inhibits chondrocyte proliferation and differentiation, leading to impaired endochondral ossification.
*Runt-related transcription factor 2*
- Mutations in **Runt-related transcription factor 2 (RUNX2)** are associated with **cleidocranial dysplasia**, a condition characterized by absent or hypoplastic clavicles, delayed closure of fontanelles, and dental abnormalities, which are not described in this patient.
- While it affects bone development, the specific features of achondroplasia, such as rhizomelic dwarfism and a prominent forehead, are not typical of RUNX2 mutations.
*Alpha-1 type I collagen*
- Mutations in **collagen genes**, particularly type I collagen (COL1A1, COL1A2), are linked to **osteogenesis imperfecta**, characterized by **fragile bones**, blue sclera, and hearing loss.
- The patient's presentation does not include these features, and the primary issue is disproportionate short stature due to impaired cartilage growth, not bone fragility.
*Insulin-like growth factor 1 receptor*
- Mutations in the **insulin-like growth factor 1 receptor (IGF1R)** can lead to **pre- and postnatal growth retardation** and microcephaly, often associated with developmental delay and feeding difficulties.
- While IGF1R mutations cause short stature, the specific skeletal dysmorphology (e.g., prominent forehead, shortened limbs) and normal intelligence are much more suggestive of achondroplasia.
*Fibrillin-1*
- Mutations in **fibrillin-1** are responsible for **Marfan syndrome**, which typically presents with **tall stature**, long limbs (dolichostenomelia), joint hypermobility, and cardiovascular abnormalities such as aortic root dilation.
- The patient's short stature and shortened limbs directly contradict the clinical picture of Marfan syndrome.
Growth/Development US Medical PG Question 5: A 10-year-old girl is admitted to the medical floor for a respiratory infection. The patient lives in a foster home and has been admitted many times. Since birth, the patient has had repeated episodes of pain/pressure over her frontal sinuses and a chronic cough that produces mucus. She was recently treated with amoxicillin for an infection. The patient is in the 25th percentile for height and weight which has been constant since birth. Her guardians state that the patient has normal bowel movements and has been gaining weight appropriately. The patient has a history of tricuspid stenosis. She also recently had magnetic resonance imaging (MRI) of her chest which demonstrated dilation of her airways. Her temperature is 99.5°F (37.5°C), blood pressure is 90/58 mmHg, pulse is 120/min, respirations are 18/min, and oxygen saturation is 94% on room air. Physical exam is notable for bruises along the patient's shins which the guardians state are from playing soccer. The rest of the exam is deferred because the patient starts crying. Which of the following findings is associated with this patient's most likely underlying diagnosis?
- A. Social withdrawal and avoidance of eye contact
- B. Hypocalcemia
- C. Repeat sinus infections secondary to seasonal allergies
- D. Diastolic murmur best heard along the right lower sternal border
- E. Increased chloride in the patient's sweat (Correct Answer)
Growth/Development Explanation: ***Increased chloride in the patient's sweat***
- The patient's history of recurrent respiratory infections, chronic productive cough, frontal sinus pain, and **bronchiectasis** (dilated airways on MRI) are highly suggestive of **cystic fibrosis**.
- **Elevated sweat chloride** is the hallmark diagnostic test for cystic fibrosis, reflecting defective chloride transport in exocrine glands.
*Social withdrawal and avoidance of eye contact*
- These are features associated with **autism spectrum disorder**, which is unrelated to the patient's respiratory and sinus symptoms.
- While possible as a co-occurring condition, it is not directly linked to the most likely **underlying diagnosis** described.
*Hypocalcemia*
- **Hypocalcemia** is typically associated with conditions like **hypoparathyroidism** or severe **vitamin D deficiency**.
- It is not a characteristic feature or direct complication of cystic fibrosis.
*Repeat sinus infections secondary to seasonal allergies*
- While seasonal allergies can cause sinus issues, the patient's history of **chronic, productive cough**, and **bronchiectasis** points to a more severe underlying condition like cystic fibrosis, not just allergies.
- Cystic fibrosis patients often have chronic sinusitis due to thick, inspissated mucus, not primarily due to allergens.
*Diastolic murmur best heard along the right lower sternal border*
- A diastolic murmur at the right lower sternal border might suggest **aortic regurgitation** or a specific type of **pulmonary regurgitation**, but it is not characteristic of the patient's known tricuspid stenosis.
- The patient has **tricuspid stenosis**, which typically causes a mid-diastolic murmur best heard at the left lower sternal border, often increasing with inspiration. This finding is unrelated to cystic fibrosis.
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