Endocrinology Practice Questions

Q: Which endocrine disorder is associated with epiphyseal dysgenesis?

Hypothyroidism. **Explanation:** **Hypothyroidism** is the correct answer because thyroid hormones are essential for normal linear growth and skeletal maturation. In congenital or juvenile hypothyroidism, there is a significant delay in the appearance of ossification centers. When these centers finally appear, they do so from multiple small foci rather than a single center. These foci fail to coalesce normally, resulting in a fragmented, stippled, or "moth-eaten" appearance on X-ray, known as **epiphyseal dysgenesis**. This is most commonly seen in the femoral head and is a hallmark radiological sign of the condition. **Why other options are incorrect:** * **Cushing’s Syndrome:** Excess glucocorticoids lead to growth failure and osteoporosis (decreased bone density), but they do not cause the specific fragmented pattern of dysgenesis seen in hypothyroidism. * **Addison’s Disease:** Chronic adrenocortical insufficiency primarily affects electrolyte balance and blood pressure; it does not typically manifest with specific epiphyseal maturation defects. * **Hypoparathyroidism:** This condition leads to hypocalcemia and hyperphosphatemia. While it may cause basal ganglia calcification or dental enamel hypoplasia, it is not associated with epiphyseal dysgenesis. **High-Yield Clinical Pearls for NEET-PG:** * **Bone Age:** In hypothyroidism, bone age is significantly delayed compared to chronological age. * **Most Common Cause:** Worldwide, iodine deficiency is the most common cause of congenital hypothyroidism; in iodine-sufficient areas, it is thyroid dysgenesis. * **Other Skeletal Findings:** Look for a "double-contoured" appearance of vertebrae or a "bullet-shaped" vertebra (T12/L1) in hypothyroid patients. * **Screening:** The best time to screen for congenital hypothyroidism is between 48–72 hours of life to avoid the physiological TSH surge.

Q: Which of the following is true in cretinism?

Prolonged physiological jaundice present. **Explanation:** Congenital hypothyroidism (Cretinism) is one of the most common preventable causes of intellectual disability. The clinical presentation is often subtle at birth due to the transplacental passage of maternal thyroid hormones. **Why Option C is Correct:** Prolonged physiological jaundice (unconjugated hyperbilirubinemia) is one of the earliest clinical signs of cretinism. Thyroid hormones are essential for the maturation of the enzyme **hepatic glucuronosyltransferase**. Deficiency leads to delayed conjugation of bilirubin, causing jaundice to persist beyond the typical 10–14 day window. **Analysis of Incorrect Options:** * **Option A:** Goiter is **not** a universal finding. While it can occur in dyshormonogenesis or maternal antithyroid drug use, the most common cause of sporadic cretinism is **thyroid dysgenesis** (aplasia, hypoplasia, or ectopy), where the thyroid gland is absent or small, meaning no goiter is present. * **Option B:** While T4 levels are low, the **gold standard screening test** and the most sensitive indicator for primary hypothyroidism is an **elevated serum TSH**. Relying solely on T4 can miss cases of mild or compensated hypothyroidism. **High-Yield Clinical Pearls for NEET-PG:** * **Most common cause:** Thyroid Dysgenesis (80-85%). * **Early Signs:** Poor feeding, lethargy, macroglossia, large posterior fontanelle (>0.5 cm), and umbilical hernia. * **Radiological Sign:** Absence of the **distal femoral epiphysis** (normally present at birth) indicates prenatal hypothyroidism. * **Treatment:** Levothyroxine (10-15 μg/kg/day) should be started immediately to prevent irreversible neurodevelopmental delay.

Q: Which of the following may be a presenting feature of phenylketonuria?

Salaam spasms. **Explanation:** **Phenylketonuria (PKU)** is an autosomal recessive inborn error of metabolism caused by a deficiency of the enzyme **phenylalanine hydroxylase (PAH)**. This leads to the accumulation of phenylalanine and its metabolites (like phenylpyruvic acid) in the blood and brain. **Why Option A is Correct:** Untreated PKU leads to severe intellectual disability and neurological manifestations. **Salaam spasms** (also known as infantile spasms or West Syndrome) are a classic neurological presentation in infants with PKU. The accumulation of phenylalanine interferes with neurotransmitter synthesis (dopamine and serotonin) and myelination, leading to hypsarrhythmia on EEG and clinical spasms. **Analysis of Incorrect Options:** * **B. Huntington’s chorea:** This is an autosomal dominant neurodegenerative disorder characterized by CAG repeats. It is unrelated to phenylalanine metabolism. * **C. Diarrhoea:** While some metabolic disorders present with GI distress, PKU is not typically associated with diarrhea. * **D. Haematemesis:** This refers to vomiting blood, usually seen in portal hypertension or peptic ulcer disease, and is not a feature of PKU. **High-Yield Clinical Pearls for NEET-PG:** * **Classic Triad:** Intellectual disability, seizures (Salaam spasms), and hypopigmentation (fair skin/blue eyes due to decreased melanin). * **Odour:** Patients often have a characteristic **"mousy" or "musty" odor** in urine and sweat. * **Diagnosis:** Guthrie test (bacterial inhibition assay) or tandem mass spectrometry for screening. * **Management:** Lifelong restriction of dietary phenylalanine (maintain levels between 2–6 mg/dL). * **Maternal PKU:** If a mother has high phenylalanine levels during pregnancy, the fetus may develop microcephaly, CHD, and growth restriction (teratogenic effect).

Q: A 5-year-old boy with IDDM (Insulin-Dependent Diabetes Mellitus) on a single morning dose of insulin has begun to have nightly enuresis. His fasting blood sugar (FBS) level generally is 200-250 mg/dl, and his blood glucose level before supper generally is 75-150 mg/dl. What is the most likely cause of this patient's enuresis?

Glycosuria from under-insulinization overnight. **Explanation:** The core issue in this clinical scenario is **inadequate insulin coverage** during the night. The patient is on a single morning dose of insulin, which typically peaks in the afternoon and wears off by the evening/night. 1. **Why Option A is correct:** The high Fasting Blood Sugar (FBS) of 200–250 mg/dl indicates that the insulin effect has dissipated overnight. When blood glucose exceeds the **renal threshold (approx. 180 mg/dl)**, glucose is excreted in the urine (glycosuria). Glucose acts as an osmotic diuretic, leading to **polyuria**. In a child, this increased urine volume during sleep manifests as secondary nocturnal enuresis. 2. **Why other options are incorrect:** * **Option B:** While chronic disease can cause psychological stress, the physiological evidence of hyperglycemia (FBS 200+) strongly points toward a metabolic cause. * **Option C:** UTIs can cause enuresis, but the classic presentation would include dysuria, frequency, or urgency, and it wouldn't explain the high FBS. * **Option D:** The **Somogyi phenomenon** refers to rebound hyperglycemia in the morning following *nocturnal hypoglycemia*. However, this patient's pre-supper glucose (75–150 mg/dl) is relatively normal/low, and a single morning dose is unlikely to cause midnight hypoglycemia followed by such high fasting levels without intermediate coverage. **Clinical Pearls for NEET-PG:** * **Renal Threshold for Glucose:** 180 mg/dl. * **Dawn Phenomenon:** Early morning hyperglycemia due to a physiological surge in growth hormone and cortisol (requires *increasing* nighttime insulin). * **Somogyi Effect:** Post-hypoglycemic hyperglycemia (requires *decreasing* nighttime insulin). * **Management:** For this patient, the best step is moving to a **split-mixed regimen** (morning and evening doses) or a basal-bolus regimen to ensure 24-hour coverage.

Q: What is the most common presentation of congenital hypothyroidism?

Asymptomatic at birth. **Explanation:** The correct answer is **D. Asymptomatic at birth.** **Why it is correct:** The most common presentation of congenital hypothyroidism (CH) is an **asymptomatic neonate**. This occurs because of the **transplacental transfer of maternal thyroid hormones (T4)**, which provides approximately 33% of normal fetal levels. This maternal contribution is sufficient to prevent clinical symptoms and protect the developing fetal brain in the immediate postnatal period, even if the infant’s thyroid gland is absent (athyreosis) or dysgenetic. **Analysis of Incorrect Options:** * **A, B, and C:** While prolonged jaundice, a wide posterior fontanelle (>0.5 cm), macroglossia, umbilical hernia, and poor feeding are classic clinical signs of CH, they are **late manifestations**. Only about 5% of affected newborns exhibit these signs in the first few days of life. If a clinician waits for these symptoms to appear, irreversible intellectual disability may have already begun. **High-Yield Clinical Pearls for NEET-PG:** * **Most Common Cause:** Thyroid Dysgenesis (80-85%), with ectopic thyroid being the most frequent subtype. * **Screening:** This is why **Universal Newborn Screening** (usually via heel prick for TSH or T4 between 48–72 hours) is critical; it identifies the condition during the asymptomatic window. * **Early Sign:** If symptoms *do* appear early, a **wide posterior fontanelle** is often the earliest physical marker. * **Treatment:** Levothyroxine (10-15 μg/kg/day) should be started immediately to ensure normal neurodevelopment.

Q: Which of the following is NOT a feature of Allgrove syndrome?

ACTH excess leading to Cushing syndrome. **Explanation:** **Allgrove Syndrome**, also known as **Triple A Syndrome**, is a rare autosomal recessive disorder caused by mutations in the *AAAS* gene on chromosome 12q13, which encodes the protein **ALADIN**. **Why Option A is correct:** The hallmark of Allgrove syndrome is **ACTH-resistant adrenal insufficiency** (Addisonian-like state), not ACTH excess. Patients suffer from a deficiency of glucocorticoids because the adrenal cortex fails to respond to ACTH. Therefore, it leads to **adrenal crisis**, not Cushing syndrome (which is characterized by cortisol excess). **Why the other options are incorrect:** * **B. Achalasia:** This is one of the three "A"s. It involves the failure of the lower esophageal sphincter to relax, leading to dysphagia. * **C. Alacrimia:** Often the earliest presenting sign, it refers to the absence or severe reduction of tear production. * **D. Hyperpigmentation:** Because the adrenal gland is resistant to ACTH, the body produces compensatory **high levels of ACTH**. High ACTH cross-reacts with melanocortin-1 receptors, leading to skin and mucosal hyperpigmentation, similar to primary adrenal insufficiency. **High-Yield Clinical Pearls for NEET-PG:** * **The 3 "A"s:** **A**chalasia, **A**lacrimia, and **A**drenal insufficiency. * **The 4th "A":** Many experts include **A**utonomic dysfunction (e.g., pupillary abnormalities, orthostatic hypotension) as a fourth feature. * **Diagnosis:** Schirmer’s test is used to confirm alacrimia. * **Management:** Glucocorticoid replacement is life-saving; mineralocorticoid function is usually preserved in these patients.

Q: A child with increased conjugated bilirubin develops seizures and cataract. What is the probable diagnosis?

Galactosemia. **Explanation:** The clinical triad of **conjugated hyperbilirubinemia (jaundice), cataracts, and seizures** (due to hypoglycemia) in an infant is a classic presentation of **Classic Galactosemia**. **1. Why Galactosemia is correct:** Galactosemia is most commonly caused by a deficiency of **Galactose-1-phosphate uridyltransferase (GALT)**. When an infant is fed breast milk or cow’s milk (containing lactose), galactose accumulates. * **Liver:** Accumulation of galactose-1-phosphate causes hepatotoxicity, leading to cholestasis and conjugated hyperbilirubinemia. * **Eyes:** Excess galactose is converted to **galactitol** by aldose reductase. Galactitol is osmotically active, drawing water into the lens and causing "oil-drop" cataracts. * **Brain:** Severe hypoglycemia occurs because accumulated phosphates inhibit glycogenolysis and gluconeogenesis, leading to seizures. **2. Why other options are incorrect:** * **Tyrosinemia (Type I):** Presents with liver failure, rickets, and a "cabbage-like" odor. While it causes jaundice, it does **not** typically cause cataracts. * **Fructosemia (Hereditary Fructose Intolerance):** Symptoms begin only after introducing fructose/sucrose (fruits/juices). It causes hypoglycemia and jaundice but **not** cataracts. * **Glycogen Storage Disorders (GSD):** GSD Type I (von Gierke) presents with massive hepatomegaly, lactic acidosis, and hypoglycemia, but typically features **unconjugated** bilirubinemia and lacks cataracts. **High-Yield Clinical Pearls for NEET-PG:** * **Deficiency:** GALT (Chromosome 9p). * **Screening:** Reducing substances in urine (Clinitest positive) while glucose oxidase (Dipstick) is negative. * **Infection Risk:** Increased susceptibility to **E. coli sepsis** (due to inhibition of leucocyte bactericidal activity). * **Management:** Immediate lifelong exclusion of lactose and galactose from the diet.

Question 1

Which endocrine disorder is associated with epiphyseal dysgenesis?

Accepted Answer

Hypothyroidism

Answer

Cushing's syndrome

Answer

Addison's disease

Answer

Hypoparathyroidism

Question 2

An 18-month-old child with ambiguous genitalia presented to the hospital. His BP is 118/78 mm Hg, serum K+ is 6 mEq/L, and serum sodium is 120 mEq/L. The patient was started on I.V. fluids. What additional specific therapy will you add?

Accepted Answer

Hydrocortisone

Answer

Potassium binding resin

Answer

Digoxin

Answer

Calcium gluconate

Question 3

Which of the following is true in cretinism?

Accepted Answer

Prolonged physiological jaundice present

Answer

Goiter present at birth

Answer

Can be diagnosed by serum T4 levels

Answer

All of the above

Question 4

Which of the following may be a presenting feature of phenylketonuria?

Accepted Answer

Salaam spasms

Answer

Huntington's chorea

Answer

Diarrhoea

Answer

Haematemesis

Question 5

A 5-year-old boy with IDDM (Insulin-Dependent Diabetes Mellitus) on a single morning dose of insulin has begun to have nightly enuresis. His fasting blood sugar (FBS) level generally is 200-250 mg/dl, and his blood glucose level before supper generally is 75-150 mg/dl. What is the most likely cause of this patient's enuresis?

Accepted Answer

Glycosuria from under-insulinization overnight

Answer

Stress of chronic disease

Answer

Urinary tract infection

Answer

Somogyi phenomenon

Question 6

Mental retardation is not a feature of which one of the following mucopolysaccharidoses?

Accepted Answer

Morquio syndrome (MPS IV)

Answer

Hurler syndrome (MPS I)

Answer

Hunter syndrome (MPS II)

Answer

Sanfilippo syndrome (MPS III)

Question 7

A 7-year-old child presents with increased thirst and enuresis. Despite increased appetite, there has been a 5-pound weight loss over the past month. A urine dipstick reveals glucosuria. What is the most likely finding in a blood sample from this patient compared to a normal individual?

Accepted Answer

Increased antibodies against glutamic acid decarboxylase (GAD)

Answer

Increased concentration of C-peptide

Answer

Decreased concentration of hemoglobin A1c

Answer

Decreased osmolarity

Question 8

What is the most common presentation of congenital hypothyroidism?

Accepted Answer

Asymptomatic at birth

Answer

Prolongation of physiological jaundice

Answer

Wide open posterior fontanelle

Answer

Enlarged tongue and feeding problems

Question 9

Which of the following is NOT a feature of Allgrove syndrome?

Accepted Answer

ACTH excess leading to Cushing syndrome

Answer

Achalasia

Answer

Alacrimia

Answer

Hyperpigmentation

Question 10

A child with increased conjugated bilirubin develops seizures and cataract. What is the probable diagnosis?

Accepted Answer

Galactosemia

Answer

Tyrosinemia

Answer

Fructosemia

Answer

Glycogen storage disorder

Endocrinology — MCQs

Endocrinology — MCQs

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