Endocrinology Practice Questions

Q: Which of the following is NOT typically seen in congenital hypothyroidism?

Short metacarpals. **Explanation:** Congenital Hypothyroidism (CH) is one of the most common treatable causes of intellectual disability. The correct answer is **Short metacarpals**, as this is a characteristic feature of **Pseudohypoparathyroidism (Albright Hereditary Osteodystrophy)** or Turner Syndrome, rather than hypothyroidism. **Why the other options are seen in Congenital Hypothyroidism:** * **Delayed bone age (A):** Thyroid hormones are essential for linear growth and epiphyseal maturation. Deficiency leads to a significant lag in bone age compared to chronological age. * **Delayed puberty (B):** Thyroid hormone is required for the normal maturation of the hypothalamic-pituitary-gonadal axis. While severe juvenile hypothyroidism can rarely cause precocious puberty (Van Wyk-Grumbach syndrome), the standard presentation of untreated hypothyroidism is delayed puberty. * **Large anterior fontanelle (D):** Delayed ossification of the skull bones leads to a large anterior fontanelle and a persistently open posterior fontanelle (a key early diagnostic clue). **Clinical Pearls for NEET-PG:** * **Most common cause:** Thyroid dysgenesis (Ectopy is the most common specific type). * **Early signs:** Prolonged physiological jaundice, poor feeding, hoarse cry, and umbilical hernia. * **Late signs:** Macroglossia, "pot-bellied" appearance, and developmental delay (Cretinism). * **Radiological sign:** Absence of the distal femoral epiphysis at birth (normally appears at 36 weeks gestation) is a strong indicator of in-utero hypothyroidism. * **Treatment:** Levothyroxine (10–15 μg/kg/day) initiated as early as possible to prevent permanent neurocognitive impairment.

Q: What is the treatment for virilizing adrenal hyperplasia?

Cortisone. **Explanation:** Virilizing Adrenal Hyperplasia (Congenital Adrenal Hyperplasia - CAH) is most commonly caused by a deficiency of the enzyme **21-hydroxylase**. This deficiency leads to impaired synthesis of cortisol. Due to the lack of negative feedback from cortisol, the pituitary gland secretes excessive **ACTH**. High ACTH levels overstimulate the adrenal cortex, causing hyperplasia and shunting steroid precursors into the androgen pathway, resulting in virilization. **Why Cortisone is correct:** The primary goal of treatment is **hormone replacement**. Administering glucocorticoids (like Cortisone, Hydrocortisone, or Prednisolone) serves two purposes: 1. It replaces the deficient physiological cortisol. 2. It provides negative feedback to the pituitary to **suppress ACTH secretion**, thereby halting the overproduction of adrenal androgens and preventing further virilization. **Why other options are incorrect:** * **Estrogens:** These do not address the underlying enzyme deficiency or the ACTH excess. * **Antiandrogens:** While they may block androgen action, they do not correct the life-threatening cortisol deficiency or the adrenal hyperplasia. * **ACTH:** Administering ACTH would worsen the condition by further stimulating the adrenal gland to produce more androgens. **High-Yield Clinical Pearls for NEET-PG:** * **Most common cause:** 21-hydroxylase deficiency (90-95% of cases). * **Diagnostic Marker:** Elevated levels of **17-hydroxyprogesterone (17-OHP)**. * **Salt-wasting type:** Occurs in 75% of cases; requires additional **Mineralocorticoid** replacement (Fludrocortisone). * **Clinical Presentation:** Ambiguous genitalia in females; precocious puberty or salt-wasting crisis (hyponatremia, hyperkalemia) in males.

Q: In a child with ambiguous genitalia, what is the first test to be done?

Karyotyping. **Explanation:** In the evaluation of a child with ambiguous genitalia, the primary goal is to determine the genetic sex and identify life-threatening conditions like salt-wasting Congenital Adrenal Hyperplasia (CAH). **Karyotyping** is considered the gold standard and the definitive first step because it establishes the chromosomal sex (46,XX or 46,XY), which dictates the entire diagnostic algorithm. Knowing the genotype is essential to differentiate between disorders of sexual development (DSD), such as 46,XX DSD (most commonly CAH) and 46,XY DSD (such as Androgen Insensitivity Syndrome). **Analysis of Incorrect Options:** * **Serum 17-hydroxyprogesterone (17-OHP):** While this is the most important biochemical test to diagnose the most common cause of ambiguous genitalia (21-hydroxylase deficiency), it is often unreliable in the first 24–48 hours of life due to maternal hormone interference. * **Serum 17-ketosteroids:** This is an outdated marker for adrenal androgen production and has been replaced by more specific assays like 17-OHP and DHEAS. * **Ultrasound Pelvis:** This is a crucial secondary step to identify the presence or absence of internal Mullerian structures (uterus/ovaries), but it is operator-dependent and does not provide the definitive genetic diagnosis required to initiate the workup. **High-Yield Clinical Pearls for NEET-PG:** * **Most common cause of ambiguous genitalia:** Congenital Adrenal Hyperplasia (specifically 21-hydroxylase deficiency). * **Most common cause of female pseudohermaphroditism:** CAH (46,XX). * **Most common cause of male pseudohermaphroditism:** Androgen Insensitivity Syndrome (46,XY). * **Emergency Management:** Any neonate with ambiguous genitalia should be monitored for an **adrenal crisis** (hyponatremia, hyperkalemia, and hypoglycemia) until CAH is ruled out.

Q: Which of the following statements about 21-alpha hydroxylase deficiency is false?

Hypokalemic alkalosis is seen. **Explanation:** **21-alpha hydroxylase deficiency** is the most common form of Congenital Adrenal Hyperplasia (CAH), accounting for over 90% of cases. The enzyme deficiency leads to a block in the conversion of progesterone to deoxycorticosterone (mineralocorticoid pathway) and 17-OH progesterone to 11-deoxycortisol (glucocorticoid pathway). **Why Option D is False (The Correct Answer):** In 21-alpha hydroxylase deficiency, there is a **deficiency of aldosterone** (mineralocorticoid). Aldosterone normally functions to retain sodium and excrete potassium/hydrogen ions. Its absence leads to "Salt Wasting," characterized by **Hyponatremia, Hyperkalemia, and Metabolic Acidosis**. Therefore, the statement "Hypokalemic alkalosis is seen" is incorrect; that presentation is actually seen in 11-beta or 17-alpha hydroxylase deficiencies where mineralocorticoid activity is increased. **Analysis of Other Options:** * **Option A:** It is indeed the most common cause (>90%) of CAH. * **Option B:** Excess 17-OH progesterone is shunted into the androgen pathway. High prenatal androgens cause virilization of female fetuses, leading to **ambiguous genitalia** (clitoromegaly, fused labia). * **Option C:** In males, excess androgens cause **isosexual precocious puberty** (early pubic hair, phallic enlargement, accelerated bone age) but with small testes. **High-Yield Clinical Pearls for NEET-PG:** * **Gold Standard Diagnosis:** Elevated serum **17-hydroxyprogesterone (17-OHP)** levels. * **Salt-Wasting Crisis:** Typically occurs in the 2nd week of life; presents with vomiting, dehydration, and shock. * **Karyotype:** Females are 46, XX (Internal genitalia like the uterus/ovaries are normal). * **Treatment:** Glucocorticoid (Hydrocortisone) to suppress ACTH and Mineralocorticoid (Fludrocortisone) for salt replacement.

Q: Coarse facies, hepatosplenomegaly, and tall QRS on ECG are characteristic features of which of the following conditions?

Hurler's disease. **Explanation:** The clinical triad of **coarse facies**, **hepatosplenomegaly**, and **tall QRS complexes** on ECG is classic for **Hurler’s Syndrome (MPS I)**. **1. Why Hurler’s Disease is Correct:** Hurler’s syndrome is a lysosomal storage disorder caused by a deficiency of **alpha-L-iduronidase**, leading to the accumulation of dermatan and heparan sulfate. * **Coarse Facies & Organomegaly:** Progressive deposition of glycosaminoglycans (GAGs) in tissues leads to characteristic facial features (depressed nasal bridge, bulging forehead) and hepatosplenomegaly. * **Cardiac Involvement:** GAG deposition in the myocardium and valves leads to hypertrophic cardiomyopathy. On an ECG, this manifests as **left ventricular hypertrophy (LVH)**, which presents as **tall QRS complexes**. **2. Why Incorrect Options are Wrong:** * **Glycogen Storage Disease Type II (Pompe Disease):** While it presents with massive cardiomegaly and tall QRS complexes (due to glycogen deposition), it typically lacks coarse facies and significant splenomegaly. * **Hunter’s Disease (MPS II):** Similar to Hurler’s but follows an **X-linked recessive** inheritance. Crucially, it **lacks corneal clouding**, which is a hallmark of Hurler’s. * **Hemochromatosis:** While it causes organomegaly and cardiomyopathy, it typically presents in adulthood with "bronze diabetes" and does not feature coarse facies or the pediatric presentation described. **Clinical Pearls for NEET-PG:** * **Hurler vs. Hunter:** "The Hunter needs his eyes to see" (Hunter has **no** corneal clouding) and "The Hunter is a male" (X-linked). * **ECG in Pompe:** Look for a **short PR interval** alongside giant QRS complexes. * **Diagnosis:** Initial screening via urinary GAGs; definitive diagnosis via enzyme assay or genetic testing.

Q: All of the following are features of Turner syndrome, EXCEPT:

Mental retardation. **Explanation:** Turner syndrome (45,X) is the most common sex chromosomal abnormality in females. The correct answer is **Mental retardation** because, unlike many other chromosomal disorders (like Down syndrome), Turner syndrome is typically associated with **normal intelligence**. While these patients may have specific learning disabilities (e.g., difficulties with visuospatial organization or non-verbal memory), global cognitive impairment or mental retardation is not a characteristic feature. **Analysis of other options:** * **Streaky gonads:** Due to accelerated oocyte atresia, the ovaries are replaced by fibrous tissue (streak gonads), leading to primary amenorrhea and hypergonadotropic hypogonadism. * **Webbed neck (Pterygium colli):** This is a classic phenotypic feature caused by lymphatic obstruction (fetal cystic hygroma) during development. * **Coarctation of aorta:** This is the most common cardiovascular malformation in Turner syndrome (occurring in ~15-20% of cases). Bicuspid aortic valve is the overall most common cardiac anomaly. **High-Yield Clinical Pearls for NEET-PG:** * **Short Stature:** The most consistent clinical finding (due to SHOX gene haploinsufficiency). * **Karyotype:** 45,X is the most common (50%), but mosaicism (45,X/46,XX) is frequent and often presents with milder features. * **Renal Anomaly:** Horseshoe kidney is the most common renal finding. * **Lymphedema:** Congenital lymphedema of hands and feet at birth is a strong diagnostic clue. * **Treatment:** Growth hormone (for height) and Estrogen replacement (for secondary sexual characteristics and bone health).

Q: An infant presents with clitoral enlargement and some degree of labial fusion. What is the initial step in the diagnostic workup?

Perform karyotype. **Explanation:** The clinical presentation of clitoral enlargement and labial fusion indicates **Disorders of Sex Development (DSD)**, specifically virilization of a female infant (ambiguous genitalia). **1. Why Karyotype is the Initial Step:** In any infant with ambiguous genitalia, the most critical first step is to determine the **genetic sex**. The karyotype (Option A) is the gold standard for defining the chromosomal sex (46,XX vs. 46,XY), which dictates the subsequent diagnostic algorithm. While Congenital Adrenal Hyperplasia (CAH) is the most common cause of ambiguous genitalia in a 46,XX infant, one cannot assume the diagnosis without first confirming the chromosomal sex to rule out conditions like Mixed Gonadal Dysgenesis or Ovotesticular DSD. **2. Why Other Options are Incorrect:** * **Option B (Ultrasound):** While useful to identify the presence of a uterus or gonads, it is operator-dependent and performed alongside or after the karyotype. * **Option C (17-OHP):** This is the specific test for 21-hydroxylase deficiency (the most common form of CAH). However, 17-OHP levels can be physiologically high in the first 24–48 hours of life, leading to false positives. It is usually performed after or in parallel with the karyotype. * **Option D (Testosterone):** This is measured to evaluate testicular function or androgen excess but is not the primary initial step in the broad workup of ambiguous genitalia. **High-Yield Clinical Pearls for NEET-PG:** * **Prader Staging:** Used to describe the degree of virilization of female genitalia (Stage 1 to 5). * **Emergency Alert:** Ambiguous genitalia + salt-wasting (hyponatremia, hyperkalemia, vomiting) = **Adrenal Crisis** (Medical Emergency). * **Most Common Cause:** 21-Hydroxylase deficiency (CAH) is the most common cause of 46,XX DSD. * **Rule of Thumb:** If gonads are palpable, it is likely a 46,XY DSD; if gonads are non-palpable, it is likely a 46,XX DSD (CAH).

Q: What is the screening test for neonatal hypothyroidism?

TSH and T4 assays on heel prick blood sample. **Explanation:** Congenital Hypothyroidism (CH) is one of the most common preventable causes of intellectual disability. Early diagnosis is critical because clinical features are often absent at birth due to the transplacental transfer of maternal thyroid hormones. **Why Option C is Correct:** The gold standard for screening is the measurement of **TSH and/or T4** using a **heel prick blood sample** collected on a filter paper (Guthrie card). * **Timing:** Ideally performed between **48 to 72 hours of life**. Screening before 48 hours is avoided to prevent false positives caused by the physiological postnatal TSH surge. * **Mechanism:** Most programs use a primary TSH screen; an elevated TSH indicates primary hypothyroidism, which is the most common form in neonates (often due to thyroid dysgenesis). **Why Other Options are Incorrect:** * **A. Blood iodine levels:** These do not reflect thyroid function and are only used for epidemiological studies of iodine deficiency. * **B. Radioiodine uptake:** This is an imaging modality used to determine the *etiology* (e.g., aplasia vs. ectopic gland) after a diagnosis is confirmed; it is never a screening tool. * **D. Ultrasound (USG):** Similar to uptake studies, USG is used for anatomical localization but cannot assess the functional status of the thyroid gland. **High-Yield Clinical Pearls for NEET-PG:** * **Most common cause:** Thyroid Dysgenesis (Ectopy is the most common specific type). * **Clinical sign:** A large posterior fontanelle (>0.5 cm) and prolonged physiological jaundice are early clues. * **Treatment:** Levothyroxine (10–15 μg/kg/day) should be started immediately to prevent permanent neurocognitive impairment. * **Target:** The goal is to normalize T4 within 2 weeks and TSH within 1 month.

Q: Which of the following is NOT a feature of Turner's syndrome?

Cubitus varus. **Explanation:** Turner’s syndrome (45,XO) is a common chromosomal abnormality characterized by the complete or partial absence of one X chromosome in females. **Why Cubitus Varus is the Correct Answer:** The characteristic elbow deformity in Turner’s syndrome is **Cubitus Valgus** (an increased carrying angle), not Cubitus varus. This occurs due to abnormal development of the trochlea. In NEET-PG, "Varus" (inward) vs. "Valgus" (outward) is a frequent distractor for Turner's syndrome questions. **Analysis of Incorrect Options:** * **Short Stature (A):** This is the most consistent clinical feature (seen in >95% of cases). It is primarily due to the haploinsufficiency of the **SHOX gene** located on the pseudoautosomal region of the X chromosome. * **Normal IQ (B):** Most patients with Turner’s syndrome have a **normal global IQ**. While they may exhibit specific neurocognitive deficits (e.g., difficulties with visuospatial tasks or mathematics), they do not typically present with generalized intellectual disability. * **Streak Ovaries (D):** Accelerated oocyte atresia leads to fibrous, non-functional "streak ovaries." This results in hypergonadotropic hypogonadism, causing primary amenorrhea and lack of secondary sexual characteristics. **High-Yield Clinical Pearls for NEET-PG:** * **Cardiac:** Bicuspid aortic valve (most common) and Coarctation of the aorta. * **Renal:** Horseshoe kidney. * **Lymphedema:** Congenital lymphedema of hands/feet and cystic hygroma (leading to "webbed neck"). * **Screening:** Karyotyping is the gold standard for diagnosis. GH therapy is used for height; Estrogen is used for pubertal induction.

Question 1

Which of the following is NOT typically seen in congenital hypothyroidism?

Accepted Answer

Short metacarpals

Answer

Delayed bone age

Answer

Delayed puberty

Answer

Large anterior fontanelle

Question 2

What is the treatment for virilizing adrenal hyperplasia?

Accepted Answer

Cortisone

Answer

Estrogens

Answer

Antiandrogens

Answer

ACTH

Question 3

A child presents with obesity, short stature, hypertension, and hyperglycemia. What is the most probable diagnosis?

Accepted Answer

Cushing's syndrome

Answer

Addison's disease

Answer

Congenital disease

Answer

Congenital adrenal hyperplasia

Question 4

In a child with ambiguous genitalia, what is the first test to be done?

Accepted Answer

Karyotyping

Answer

Serum 17-hydroxyprogesterone

Answer

Serum 17-ketosteroids

Answer

Ultrasound pelvis

Question 5

Which of the following statements about 21-alpha hydroxylase deficiency is false?

Accepted Answer

Hypokalemic alkalosis is seen

Answer

Most common cause of Congenital Adrenal Hyperplasia (CAH) in children

Answer

Affected females present with ambiguous genitalia

Answer

Affected males present with precocious puberty

Question 6

Coarse facies, hepatosplenomegaly, and tall QRS on ECG are characteristic features of which of the following conditions?

Accepted Answer

Hurler's disease

Answer

Glycogen storage disease type II

Answer

Hunter's disease

Answer

Hemochromatosis

Question 7

All of the following are features of Turner syndrome, EXCEPT:

Accepted Answer

Mental retardation

Answer

Streaky gonads

Answer

Webbed neck

Answer

Coarctation of aorta

Question 8

An infant presents with clitoral enlargement and some degree of labial fusion. What is the initial step in the diagnostic workup?

Accepted Answer

Perform karyotype

Answer

Perform ultrasound scan

Answer

Measure serum 17-hydroxyprogesterone levels

Answer

Measure serum testosterone levels

Question 9

What is the screening test for neonatal hypothyroidism?

Accepted Answer

TSH and T4 assays on heel prick blood sample

Answer

Blood iodine levels

Answer

Radioiodine uptake

Answer

Ultrasound (USG)

Question 10

Which of the following is NOT a feature of Turner's syndrome?

Accepted Answer

Cubitus varus

Answer

Short stature

Answer

Normal IQ

Answer

Streak ovaries

Endocrinology — MCQs

Endocrinology — MCQs

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