Endocrinology Practice Questions

Q: All of the following are associated with Turner's syndrome except?

Cubitus varus. **Explanation:** Turner’s Syndrome (45, XO) is a common cause of primary amenorrhea and short stature due to the loss of genetic material on the X chromosome. **Why "Cubitus varus" is the correct answer:** The characteristic skeletal deformity in Turner’s syndrome is **Cubitus valgus** (an increased carrying angle of the elbow), not cubitus varus. Cubitus varus (gunstock deformity) is typically a late complication of a supracondylar fracture of the humerus, not a genetic feature of Turner’s. **Analysis of incorrect options:** * **Primary amenorrhea:** This is a hallmark feature. Patients have "streak ovaries" (gonadal dysgenesis) where ovarian follicles are replaced by fibrous tissue, leading to hypergonadotropic hypogonadism. * **Short stature:** This is the most consistent clinical finding in Turner’s syndrome, primarily due to the haploinsufficiency of the **SHOX gene**. * **Aortic coarctation:** This is the most classic cardiovascular association (found in ~10-20% of cases). Bicuspid aortic valve is actually the most common cardiac anomaly overall. **NEET-PG High-Yield Pearls:** * **Karyotype:** 45, XO is most common; however, mosaicism (45,X/46,XX) may present with secondary amenorrhea. * **Cardiac:** Bicuspid aortic valve (most common) > Coarctation of aorta. * **Renal:** Horseshoe kidney is the most common renal anomaly. * **Physical Signs:** Webbed neck (pterygium colli), low posterior hairline, shield chest (widely spaced nipples), and shortened 4th metacarpals. * **Management:** Growth hormone for height; Estrogen/Progesterone for secondary sexual characteristics; Oocyte donation for pregnancy.

Q: What is the immediate treatment for a 10 kg infant presenting with tetany?

Intravenous calcium gluconate with cardiac monitoring. ### Explanation **Correct Answer: B. Intravenous calcium gluconate with cardiac monitoring** **Medical Concept:** Tetany in an infant is a clinical manifestation of **hypocalcemia**, characterized by increased neuromuscular irritability (carpopedal spasm, laryngospasm, or seizures). The immediate priority is to restore serum ionized calcium levels to prevent life-threatening complications like laryngeal stridor or cardiac arrhythmias. **Intravenous Calcium Gluconate (10%)** is the drug of choice. The standard dose is **1–2 ml/kg (100–200 mg/kg)**, administered slowly over 10–20 minutes. **Continuous cardiac monitoring** is mandatory because rapid infusion can cause bradycardia, heart block, or even cardiac arrest. **Why other options are incorrect:** * **A & C (Diazepam/Phenobarbital):** These are anti-epileptic drugs used for status epilepticus or febrile seizures. While tetany can present with seizures, the underlying cause is metabolic (low calcium). Treating with sedatives without correcting the calcium deficit will not resolve the tetany and may delay life-saving treatment. * **D (Wait and watch):** Tetany is a medical emergency. Delaying treatment can lead to airway obstruction (laryngospasm) or permanent neurological damage from hypocalcemic seizures. **NEET-PG High-Yield Pearls:** * **ECG Finding:** The classic sign of hypocalcemia is **prolonged QTc interval**. * **Administration Tip:** Always dilute calcium gluconate (usually 1:1 with 5% Dextrose or Normal Saline) and check for IV patency, as extravasation causes severe **tissue necrosis**. * **Refractory Hypocalcemia:** If calcium levels do not improve despite replacement, check **Magnesium levels**. Hypomagnesemia must be corrected first for calcium therapy to be effective. * **Chvostek’s and Trousseau’s signs** are clinical markers of latent tetany.

Q: A 13-year-old boy presented with episodes of headache, abdominal pain, palpitations, excessive sweating, and dizziness. He is also noted to have poor weight gain. On examination, he is hypertensive with tremors. What is the likely cause of the child's condition?

Pheochromocytoma. **Explanation:** The clinical presentation of paroxysmal headache, palpitations, excessive sweating (the classic triad), and hypertension strongly suggests **Pheochromocytoma**. This is a catecholamine-secreting tumor arising from chromaffin cells of the adrenal medulla (or extra-adrenal sympathetic chain). In children, the excess secretion of epinephrine and norepinephrine leads to a hypermetabolic state, explaining the poor weight gain and tremors, alongside episodic sympathetic overactivity. **Analysis of Options:** * **Pheochromocytoma (Correct):** The symptoms are a direct result of "catecholamine surges." Hypertension in children is often secondary; when combined with the classic triad and weight loss, pheochromocytoma is the most likely diagnosis. * **Diabetes Mellitus:** While it causes weight loss and polyuria, it does not typically present with paroxysmal hypertension or the classic sympathetic triad. * **Hysterical Fainting Spells:** These are diagnoses of exclusion. The presence of objective hypertension and tremors points toward an organic, endocrine cause rather than a psychogenic one. * **Hypothyroidism:** This typically presents with weight gain, bradycardia, lethargy, and cold intolerance—the exact opposite of this patient’s hyperdynamic state. **NEET-PG High-Yield Pearls:** * **Rule of 10s:** 10% are bilateral, 10% are malignant, 10% are extra-adrenal (Paragangliomas), and 10% are familial. Note: In children, the incidence of extra-adrenal and bilateral tumors is higher (approx. 25%). * **Diagnosis:** Best initial screening test is **24-hour urinary fractionated metanephrines** or plasma free metanephrines. * **Localization:** MIBG scan is used if CT/MRI fails to locate the tumor. * **Management:** Always give **Alpha-blockers (Phenoxybenzamine)** before Beta-blockers to avoid an unmatched alpha-constriction hypertensive crisis.

Q: A child presented with clinical features of rickets but low level of serum alkaline phosphatase. What is the most likely diagnosis?

Hypophosphatasia. **Explanation:** The hallmark of almost all forms of rickets (nutritional or genetic) is an **elevated serum Alkaline Phosphatase (ALP)**, which reflects increased osteoblastic activity. The presence of rachitic clinical features (e.g., bow legs, rachitic rosary) paired with a **low serum ALP** is pathognomonic for **Hypophosphatasia**. **1. Why Hypophosphatasia is correct:** Hypophosphatasia is a rare genetic disorder caused by a mutation in the *ALPL* gene, leading to a deficiency of the **Tissue Non-Specific Alkaline Phosphatase (TNSALP)** enzyme. This enzyme is crucial for mineralizing osteoid. Its deficiency leads to the accumulation of inorganic pyrophosphate (a potent inhibitor of mineralization), resulting in rickets-like skeletal deformities and premature loss of deciduous teeth. **2. Why the other options are incorrect:** * **Primary Biliary Cirrhosis:** This is a cholestatic liver disease. Cholestasis typically causes a significant **increase** in ALP due to impaired bile flow. * **Hyperparathyroidism:** High levels of Parathyroid Hormone (PTH) increase bone turnover, which typically leads to **elevated** ALP levels. * **Benign Familial Hyperphosphatasemia:** As the name suggests, this is characterized by persistently **high** levels of serum ALP in asymptomatic individuals, with no evidence of bone or liver disease. **NEET-PG High-Yield Pearls:** * **Biochemical Triad of Hypophosphatasia:** Low serum ALP, elevated urinary phosphoethanolamine, and elevated serum pyridoxal-5-phosphate (Vitamin B6). * **Clinical Clue:** Early loss of primary teeth (incisors) with the root intact is a classic sign. * **Differential for Low ALP:** Hypophosphatasia, severe hypothyroidism (cretinism), scurvy, severe magnesium deficiency, and zinc deficiency.

Q: Which of the following is NOT a symptom of neonatal hypothyroidism?

Hypertonia. **Explanation:** Congenital hypothyroidism (CH) is one of the most common treatable causes of intellectual disability. The clinical presentation is often subtle at birth due to the protective effect of maternal thyroid hormones. **Why Hypertonia is the correct answer:** Hypothyroidism leads to a generalized slowing of metabolic processes and neuromuscular activity. Therefore, affected neonates typically present with **hypotonia** (floppiness) rather than hypertonia. Hypertonia is more characteristic of upper motor neuron lesions or certain metabolic disorders, but not hypothyroidism. **Analysis of Incorrect Options:** * **Open posterior fontanelle:** Delayed skeletal maturation is a hallmark of CH. A posterior fontanelle larger than 0.5 cm is a highly sensitive early clinical sign. * **Large tongue (Macroglossia):** This occurs due to the accumulation of glycosaminoglycans (myxedema) in the tissues. It can lead to feeding difficulties and respiratory obstruction. * **Short stature:** Thyroid hormone is essential for linear bone growth and epiphyseal maturation. Deficiency leads to growth retardation and limb-to-trunk disproportion. **High-Yield Clinical Pearls for NEET-PG:** * **Most common cause:** Dysgenesis (Aplasia, hypoplasia, or ectopic gland) is the most common cause of permanent CH. * **Early signs:** Prolonged physiological jaundice (due to delayed glucuronyl transferase activity), umbilical hernia, constipation, and a hoarse cry. * **Diagnosis:** Newborn screening (TSH/T4) is gold standard. Treatment must start within **2 weeks** of life to prevent permanent neurocognitive impairment. * **Radiological sign:** Absence of the distal femoral epiphysis on X-ray at birth (normally present at 36 weeks gestation) indicates intrauterine hypothyroidism.

Q: A 15-day-old neonate presents with seizures. Laboratory findings show serum calcium of 5 mg/dL, serum phosphate of 9 mg/dL, and intact PTH of 30 pg/mL (Normal intact PTH = 10-60 pg/mL). What is the most likely diagnosis?

Hypoparathyroidism. ### Explanation The clinical presentation of seizures in a 15-day-old neonate with **hypocalcemia** (5 mg/dL) and **hyperphosphatemia** (9 mg/dL) points toward a defect in the Parathyroid Hormone (PTH) axis. **1. Why Hypoparathyroidism is correct:** In the presence of significant hypocalcemia, the physiological response of a healthy parathyroid gland is to secrete high levels of PTH (secondary hyperparathyroidism). In this case, the PTH is **30 pg/mL**, which is within the "normal" range. However, a normal PTH level in the setting of profound hypocalcemia is **inappropriate** and indicates a failure of the gland to respond, confirming **Hypoparathyroidism**. **2. Why the other options are incorrect:** * **Pseudohypoparathyroidism:** This is characterized by end-organ resistance to PTH. Laboratory findings would show hypocalcemia and hyperphosphatemia, but the **PTH level would be markedly elevated**. * **Vitamin D deficiency:** This typically presents with hypocalcemia and **hypophosphatemia** (due to secondary hyperparathyroidism causing phosphate wasting in the urine). PTH would be elevated. * **Hypoxic Ischemic Encephalopathy (HIE):** While HIE can cause neonatal seizures and metabolic disturbances, the specific biochemical pattern of inappropriately normal PTH with hyperphosphatemia specifically localizes the pathology to the parathyroid glands. **Clinical Pearls for NEET-PG:** * **PTH-Calcium Relationship:** Always interpret PTH in the context of serum calcium. A "normal" PTH during hypocalcemia is always pathological. * **DiGeorge Syndrome:** In a neonate with hypoparathyroidism, always look for associated features like congenital heart disease (CATCH-22) and immune deficiency. * **Early vs. Late Neonatal Tetany:** Early-onset (first 72 hours) is often due to prematurity or maternal diabetes; late-onset (after 72 hours) is often due to high phosphate intake (cow's milk) or primary hypoparathyroidism.

Q: All of the following are seen in McCune Albright Syndrome except?

GnRH-dependent sexual precocity. **Explanation:** McCune-Albright Syndrome (MAS) is a rare genetic disorder caused by a post-zygotic somatic mutation in the **GNAS gene**. This mutation leads to constitutive activation of the **Gs-alpha protein**, resulting in the overproduction of cAMP. This stimulates various endocrine glands to function independently of their stimulating hormones. **Why Option D is the Correct Answer:** In MAS, the ovaries produce estrogen autonomously without stimulation from the pituitary gland. Therefore, it causes **GnRH-independent (Peripheral) Precocious Puberty**. Because the high levels of peripheral estrogen suppress the hypothalamic-pituitary axis via negative feedback, GnRH levels remain low. **GnRH-dependent (Central) precocity** is not a primary feature of the syndrome. **Analysis of Incorrect Options:** * **A. Polyostotic fibrous dysplasia:** This is a classic component of the MAS triad where normal bone is replaced by fibrous tissue, leading to fractures and deformities. * **B. Cafe-au-lait spots:** These are hyperpigmented skin lesions characterized by irregular "Coast of Maine" borders (unlike the smooth "Coast of California" borders seen in Neurofibromatosis). * **C. GnRH-independent sexual precocity:** This is the hallmark endocrine manifestation of MAS. In girls, it typically presents as recurrent follicular cysts and vaginal bleeding. **High-Yield Clinical Pearls for NEET-PG:** * **Triad of MAS:** Polyostotic fibrous dysplasia, Cafe-au-lait spots, and Hyperfunctioning endocrinopathies (most commonly Peripheral Precocious Puberty). * **Genetic Basis:** Somatic mutation in GNAS1 gene (not inherited). * **Other Endocrine Associations:** Hyperthyroidism, Growth Hormone excess (Acromegaly), and Cushing Syndrome. * **Treatment for Precocity:** Aromatase inhibitors (e.g., Letrozole) or Estrogen receptor modulators (e.g., Tamoxifen) are used to block the effects of autonomous estrogen.

Q: Hypercalcemia is seen in which of the following conditions?

Williams syndrome. ### Explanation **Correct Answer: D. Williams Syndrome** **Williams Syndrome** (also known as Williams-Beuren syndrome) is a multisystem genetic disorder caused by a microdeletion on chromosome **7q11.23** (involving the elastin gene). A classic metabolic feature of this syndrome, especially during infancy, is **idiopathic infantile hypercalcemia**. While the exact mechanism is not fully understood, it is thought to involve increased intestinal absorption of calcium and abnormal vitamin D metabolism. The hypercalcemia usually resolves by age 2–4 but can lead to nephrocalcinosis if severe. **Analysis of Incorrect Options:** * **A. Renal Osteodystrophy:** This typically presents with **hypocalcemia** (due to phosphate retention and decreased 1,25-dihydroxyvitamin D production) and secondary hyperparathyroidism. * **B. Vitamin D Resistant Rickets (Hypophosphatemic Rickets):** This is characterized by renal phosphate wasting. Calcium levels are typically **normal** or slightly low, but never high. * **C. Hypoparathyroidism:** A deficiency in Parathyroid Hormone (PTH) leads directly to **hypocalcemia** and hyperphosphatemia, as PTH is the primary hormone responsible for raising serum calcium. **High-Yield Clinical Pearls for NEET-PG:** * **Williams Syndrome Triad:** 1. **Elfin facies:** Full cheeks, wide mouth, prominent lips, and stellate iris pattern. 2. **Cardiovascular defects:** Most commonly **Supravalvular Aortic Stenosis (SVAS)** and peripheral pulmonary artery stenosis. 3. **Behavioral profile:** "Cocktail party personality" (extremely friendly/gregarious) with developmental delay. * **Mnemonic for Hypercalcemia:** "Stones (renal), Bones (pain), Groans (abdominal pain/constipation), and Psychic Moans (confusion)."

Question 1

All of the following are associated with Turner's syndrome except?

Accepted Answer

Cubitus varus

Answer

Primary amenorrhea

Answer

Short stature

Answer

Aortic coarctation

Question 2

What is the commonest cause of primary amenorrhea with ambiguous genitalia in a female with 46XX chromosomes?

Accepted Answer

21-hydroxylase deficiency

Answer

17-hydroxylase deficiency

Answer

11-hydroxylase deficiency

Answer

Desmolase hydroxylase deficiency

Question 3

A 1-year-old child presents with thyroid swelling, abnormal weight gain, and poor activity. Laboratory tests reveal elevated TSH and very low T4. What is the most likely cause of this child's condition?

Accepted Answer

Dyshormonogenesis

Answer

Hypothalamic disease

Answer

Thyroid dysgenesis

Answer

End organ receptor insensitivity

Question 4

What is the immediate treatment for a 10 kg infant presenting with tetany?

Accepted Answer

Intravenous calcium gluconate with cardiac monitoring

Answer

Intravenous Diazepam

Answer

Intravenous slow phenobarbital

Answer

Wait and watch

Question 5

A 13-year-old boy presented with episodes of headache, abdominal pain, palpitations, excessive sweating, and dizziness. He is also noted to have poor weight gain. On examination, he is hypertensive with tremors. What is the likely cause of the child's condition?

Accepted Answer

Pheochromocytoma

Answer

Diabetes mellitus

Answer

Hysterical fainting spells

Answer

Hypothyroidism

Question 6

A child presented with clinical features of rickets but low level of serum alkaline phosphatase. What is the most likely diagnosis?

Accepted Answer

Hypophosphatasia

Answer

Primary biliary cirrhosis

Answer

Hyperparathyroidism

Answer

Benign familial hyperphosphatasemia

Question 7

Which of the following is NOT a symptom of neonatal hypothyroidism?

Accepted Answer

Hypertonia

Answer

Open posterior fontanelle

Answer

Large tongue

Answer

Short stature

Question 8

A 15-day-old neonate presents with seizures. Laboratory findings show serum calcium of 5 mg/dL, serum phosphate of 9 mg/dL, and intact PTH of 30 pg/mL (Normal intact PTH = 10-60 pg/mL). What is the most likely diagnosis?

Accepted Answer

Hypoparathyroidism

Answer

Pseudohypoparathyroidism

Answer

Vitamin D deficiency

Answer

Hypoxic Ischemic Encephalopathy

Question 9

All of the following are seen in McCune Albright Syndrome except?

Accepted Answer

GnRH-dependent sexual precocity

Answer

Polyostotic fibrous dysplasia

Answer

Cafe-au-lait spots

Answer

GnRH-independent sexual precocity

Question 10

Hypercalcemia is seen in which of the following conditions?

Accepted Answer

Williams syndrome

Answer

Renal osteodystrophy

Answer

Vitamin D resistant rickets

Answer

Hypoparathyroidism

Endocrinology — MCQs

Endocrinology — MCQs

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