Endocrinology — MCQs

Endocrinology Indian Medical PG Practice Questions and MCQs

Question 261: An eight-year-old girl presented by her mother with sexual precocity. She may have the following disorder:

A. Addison's disease
B. Neuroblastoma
C. Hyperthyroidism
D. McCune Albright syndrome (Correct Answer)

Explanation: ***McCune Albright syndrome*** - This syndrome is characterized by a triad of **fibrous dysplasia**, **café-au-lait spots**, and **precocious puberty**, which fits the clinical picture of an 8-year-old girl with sexual precocity. - The precocious puberty in McCune-Albright syndrome is typically **gonadotropin-independent**, meaning it originates from the ovaries due to overactivity rather than pituitary stimulation. *Addison's disease* - Addison's disease involves **adrenal insufficiency**, leading to symptoms like fatigue, weight loss, and hyperpigmentation, but it typically does not cause sexual precocity. - It would be associated with low **cortisol** and high **ACTH** levels, which are not indicative of premature sexual development. *Neuroblastoma* - **Neuroblastoma** is a childhood cancer that can cause symptoms due to catecholamine secretion or mass effect, but it does not directly cause sexual precocity. - While it can be associated with paraneoplastic syndromes, precocious puberty is not a typical manifestation. *Hyperthyroidism* - **Hyperthyroidism** in children can present with symptoms like weight loss, tachycardia, and goiter, but it is not a direct cause of sexual precocity. - While thyroid hormones influence growth and development, they do not typically trigger premature pubertal changes.

Question 262: Serum glucose level in children > 2 months defining hypoglycemia is?

A. < 40 mg/dL
B. < 50 mg/dL
C. < 45 mg/dL
D. < 54 mg/dL (Correct Answer)

Explanation: ***< 54 mg/dL*** - Hypoglycemia in children older than 2 months is generally defined as a **serum glucose level below 54 mg/dL (3.0 mmol/L)**. - This threshold is associated with the onset of **neuroglycopenic symptoms** and requires intervention. *< 40 mg/dL* - This level is considered **severe hypoglycemia** and requires immediate treatment, but it is not the general threshold for defining hypoglycemia in children older than 2 months. - While concerning, a value of 40 mg/dL would already be well below the established diagnostic cutoff. *< 50 mg/dL* - While close to the accepted threshold, **50 mg/dL is not the most accurate or widely recognized cutoff** for defining hypoglycemia in this age group. - Using a slightly higher threshold helps ensure **earlier identification and intervention**, preventing severe outcomes. *< 45 mg/dL* - Similar to 40 mg/dL, 45 mg/dL represents a concerning level of glucose but is **not the primary diagnostic cutoff** for hypoglycemia in children over 2 months. - The threshold of 54 mg/dL is designed to capture cases before they reach more critical levels.

Question 263: A 10 year old boy is having polyuria, polydipsia, laboratory data showed (in mEq/lit) – Na+ 154, K+ 4.5, HCO3- 22, Serum osmolality – 295 mOsm/kg, Blood urea – 50 mg/dl, Urine specific gravity – 1.005. The likely diagnosis is –

A. Barter's syndrome
B. Recurrent UTI
C. Diabetes insipidus (Correct Answer)
D. Renal tubular acidosis

Explanation: ***Diabetes insipidus*** - The classic presentation of **polyuria and polydipsia** with **hypernatremia (Na+ 154 mEq/L)** and **low urine specific gravity (1.005)** indicates inability to concentrate urine. - The **serum osmolality of 295 mOsm/kg** (upper limit of normal) in the context of hypernatremia suggests inadequate water reabsorption, consistent with **diabetes insipidus (either central or nephrogenic)**. - The dilute urine despite elevated serum sodium is pathognomonic for DI. *Barter's syndrome* - Characterized by **hypokalemic metabolic alkalosis**, increased renin and aldosterone, and normal to low blood pressure. - The given laboratory values show **normal potassium (4.5 mEq/L)** and **normal bicarbonate (22 mEq/L)**, ruling out Barter's syndrome. - Results from defects in the **Na-K-2Cl cotransporter** in the thick ascending limb of loop of Henle. *Recurrent UTI* - While UTIs may cause polyuria and polydipsia, they typically present with **dysuria, fever, urgency, and pyuria/bacteriuria**. - UTIs do not cause **hypernatremia** or the specific pattern of dilute urine with elevated serum sodium. - The clinical picture does not suggest infectious etiology. *Renal tubular acidosis* - RTA presents with **metabolic acidosis** (low bicarbonate, typically <15-18 mEq/L) with normal anion gap. - The **normal bicarbonate level (22 mEq/L)** excludes RTA. - Often associated with hypokalemia, growth retardation, and nephrocalcinosis in children.

Question 264: Which is false in Congenital Hypopituitarism?

A. Hypoglycemia
B. Growth hormone level < 7 ng/ml
C. Baby small at birth (Correct Answer)
D. Delayed puberty

Explanation: ***Baby small at birth*** - This statement is **false** because congenital hypopituitarism typically does not cause **intrauterine growth restriction** or a baby to be small at birth. - Growth hormone (GH) and other pituitary hormones are primarily involved in **postnatal growth**, so infants with this condition are usually of **normal size at birth**. *Hypoglycemia* - **Neonatal hypoglycemia** is a common and often severe manifestation of congenital hypopituitarism, especially due to **GH deficiency** and sometimes ACTH deficiency. - GH and cortisol play crucial roles in **glucose homeostasis**, and their deficiency leads to impaired gluconeogenesis. *Growth hormone level < 7 ng/ml* - A **peak growth hormone level of less than 7 ng/ml** in response to two provocative tests is a common diagnostic criterion for **growth hormone deficiency** in children. - This threshold indicates an inadequate secretion of GH essential for normal growth and metabolism. *Delayed puberty* - **Deficiency of gonadotropins** (LH and FSH) due to hypopituitarism prevents the normal onset and progression of puberty. - This results in features such as **absent or delayed secondary sexual characteristic**s and **incomplete pubertal development**.

Question 265: What percentage of the total daily dose is given as basal insulin in a basal-bolus regimen in children?

A. 25 – 50% (Correct Answer)
B. 50 – 75%
C. 0 – 25%
D. 75 – 100%

Explanation: ***25 – 50%*** - In children undergoing a **basal-bolus insulin regimen**, the basal insulin typically accounts for **25-50%** of the total daily insulin dose. - This lower percentage compared to adults (who often receive 50%) helps prevent **hypoglycemia** due to unpredictable activity levels and changing insulin sensitivities in children. *50 – 75%* - This range is generally considered too high for basal insulin in children, significantly increasing the risk of **hypoglycemia**. - While adults might approach 50% for basal insulin, the **metabolic needs** and **activity levels** of children necessitate a lower proportion to maintain safety. *0 – 25%* - A basal insulin percentage in this range is generally too low to provide adequate background glycemic control, potentially leading to **hyperglycemia** between meals and overnight. - Insufficient basal insulin would compromise the foundational control necessary for a successful **basal-bolus regimen**. *75 – 100%* - This range is far too high for basal insulin and would leave insufficient insulin for **bolus coverage** of meals. - Such a regimen would defeat the purpose of a basal-bolus approach and create severe risk of **hypoglycemia** during fasting periods.

Question 266: All of the following may be causes of precocious puberty in girls, except:

A. Granulosa cell tumor of the ovary
B. Turner syndrome (Correct Answer)
C. McCune-Albright syndrome
D. Hypothalamic hamartoma

Explanation: ***Turner syndrome*** - **Turner syndrome** (45,XO) is a genetic condition typically associated with **gonadal dysgenesis**, leading to ovarian failure and **primary amenorrhea**, not precocious puberty. - Girls with Turner syndrome usually experience **delayed puberty** or absent puberty, often requiring hormone replacement therapy. *Granulosa cell tumor of the ovary* - **Granulosa cell tumors** are sex cord-stromal tumors that can produce large amounts of **estrogen**. - This excess estrogen can lead to signs of **precocious puberty** in young girls, such as breast development and vaginal bleeding. *McCune-Albright syndrome* - **McCune-Albright syndrome** is a genetic disorder characterized by the triad of **polyostotic fibrous dysplasia**, **café-au-lait spots**, and **endocrinopathies**, including precocious puberty. - The precocious puberty in this syndrome is typically **gonadotropin-independent**, resulting from autonomous estrogen production by the ovaries. *Hypothalamic hamartoma* - A **hypothalamic hamartoma** is a benign tumor-like malformation of neural tissue in the hypothalamus. - It can secrete **gonadotropin-releasing hormone (GnRH)**, leading to central (gonadotropin-dependent) precocious puberty.

Question 267: The commonest cause of congenital hypothyroidism is -

A. Pendred syndrome
B. Deficiency of deiodinase
C. Defective release
D. Thyroid dysgenesis (Correct Answer)

Explanation: ***Thyroid dysgenesis*** - **Thyroid dysgenesis** refers to developmental abnormalities of the thyroid gland, including **agenesis** (complete absence), **hypoplasia** (underdevelopment), or **ectopic location**. - It accounts for approximately **85% of permanent congenital hypothyroidism** cases, making it the most common cause. *Pendred syndrome* - Pendred syndrome is an **autosomal recessive disorder** characterized by **sensorineural hearing loss** and thyroid goiter with mild to moderate hypothyroidism. - While it causes congenital hypothyroidism, it is due to a defect in **iodide organification** and is far less common than thyroid dysgenesis. *Deficiency of deiodinase* - **Deiodinase enzymes** are responsible for converting T4 to the more active T3 or inactivating thyroid hormones. - While a deficiency can lead to altered thyroid hormone metabolism, it is a **rare cause** of congenital hypothyroidism compared to thyroid dysgenesis. *Defective release* - **Defective release** of thyroid hormones can occur in various conditions, but it is not the most common underlying cause of congenital hypothyroidism itself. - This could be due to issues with **thyroglobulin synthesis**, processing, or secretion, but developmental abnormalities are more prevalent.

Question 268: Which of the following statements are True or False about Cretinism? 1. Goitre present at birth 2. Can be diagnosed by serum T4 levels 3. Most commonly seen in Iodine deficiency endemic areas 4. Skeletal development is delayed 5. Physiological jaundice is prolonged

A. 1,2,3 False & 4,5 True
B. 3,4,5 True & 1,2 False (Correct Answer)
C. 1,2,3 True & 4,5 False
D. 1,4,5 True & 2,3 False

Explanation: ***3,4,5 True & 1,2 False*** - **Statement 1 (FALSE): Goiter is rarely present at birth** in congenital hypothyroidism because most cases involve thyroid dysgenesis (agenesis or hypoplasia), not compensatory hyperplasia. Goitrous cretinism can occur in endemic iodine deficiency but is less common than athyreotic forms. - **Statement 2 (FALSE): Cannot be diagnosed by serum T4 levels alone**. Diagnosis requires **elevated TSH (primary screening test) along with low T4** for confirmation. T4 measurement alone is insufficient because it doesn't indicate whether the hypothyroidism is primary (thyroid failure) or secondary (pituitary/hypothalamic). Elevated TSH is the key diagnostic marker. - **Statement 3 (TRUE): Iodine deficiency** remains the most common cause of congenital hypothyroidism globally, especially in endemic areas where maternal iodine deficiency impairs fetal thyroid hormone synthesis. In iodine-sufficient developed countries, thyroid dysgenesis is more common. - **Statement 4 (TRUE): Skeletal development is delayed** due to the critical role of thyroid hormones in bone growth and maturation. This manifests as delayed epiphyseal ossification, delayed bone age, and potential short stature if untreated. - **Statement 5 (TRUE): Physiological jaundice is often prolonged** in infants with congenital hypothyroidism due to delayed hepatic maturation affecting bilirubin conjugation and excretion, processes influenced by thyroid hormones. *1,2,3 False & 4,5 True* - Incorrectly marks statement 3 as false - iodine deficiency IS the most common cause globally in endemic areas. *1,2,3 True & 4,5 False* - Incorrectly states goiter is present at birth (rare), that T4 alone can diagnose (needs TSH), and incorrectly marks the well-established delayed skeletal development and prolonged jaundice as false. *1,4,5 True & 2,3 False* - Incorrectly states goiter is present at birth and incorrectly marks iodine deficiency (the most common global cause) as false.

Question 269: Clinical features of "hypothyroidism" in a newborn are all except:

A. Large tongue
B. Mental retardation (Correct Answer)
C. Large posterior fontanel
D. Sluggishness +++

Explanation: ***Correct Answer: Mental retardation*** - **Mental retardation** is a *consequence* of **untreated** congenital hypothyroidism that develops over months to years, rather than a direct *clinical feature* present at birth in a newborn. - The other symptoms listed represent **initial clinical signs** observable in the neonatal period, which if not addressed through early thyroid replacement therapy, can lead to irreversible neurodevelopmental delay. - **Key Point:** Mental retardation develops due to insufficient thyroid hormone for critical brain development during the first 2-3 years of life, but is NOT a feature seen at birth. *Incorrect: Large tongue (Macroglossia)* - A **large, protruding tongue (macroglossia)** is a characteristic clinical feature often observed in newborns with **congenital hypothyroidism**. - This is due to the accumulation of **glycosaminoglycans (hyaluronic acid and chondroitin sulfate)** in connective tissues, leading to tissue enlargement. - This is one of the **classic physical findings** that can be detected during neonatal examination. *Incorrect: Large posterior fontanel* - A **large posterior fontanel** is a common physical finding in newborns with **congenital hypothyroidism**. - This is due to **delayed bone ossification and skeletal maturation**, a hallmark of inadequate thyroid hormone action. - The anterior fontanel may also be enlarged, and there may be wide sutures and delayed closure. *Incorrect: Sluggishness +++* - **Sluggishness** (lethargy, hypotonia, decreased activity) is a prominent and early neurological sign of **congenital hypothyroidism** in newborns. - It reflects the generalized slowing of metabolic processes and decreased central nervous system activity due to low thyroid hormone levels. - Other features include poor feeding, prolonged jaundice, constipation, and hoarse cry.

Question 270: Precocious puberty in a girl is defined as breast development before the age of?

A. 10 years
B. 8 years (Correct Answer)
C. 6 years
D. 12 years

Explanation: ***8 years*** - **Precocious puberty** in girls is traditionally defined as the development of secondary sexual development, such as **breast development** (thelarche), before the age of **8 years** [1]. - This age cut-off is based on population studies identifying when pubertal changes typically begin in the majority of girls, though studies suggest earlier onset in some populations [1]. *10 years* - This age is outside the typical definition for **precocious puberty** in girls, as most girls will have begun puberty by this age [2]. - Development of breasts at 10 years would generally be considered within the **normal range** of pubertal onset, which is typically between 8 to 13 years [2]. *6 years* - While **puberty at 6 years** would certainly be classified as precocious, the general definition uses **8 years** as the boundary [1]. - Puberty occurring before 6 years would be considered **very early precocious puberty** and warrant thorough investigation; however, benign premature thelarche is most common between 6 months and 3 years [3]. *12 years* - Pubertal development at 12 years is well within the **normal range** for female puberty [2]. - This age is frequently associated with the onset of **menarche** (first menstruation) rather than initial breast development.

Practice by Chapter

Disorders of Growth

Practice Questions

Thyroid Disorders

Practice Questions

Disorders of Puberty

Practice Questions

Adrenal Disorders

Practice Questions

Diabetes Mellitus in Children

Practice Questions

Disorders of Calcium and Phosphate Metabolism

Practice Questions

Disorders of Sexual Development

Practice Questions

Hypoglycemia

Practice Questions

Obesity and Metabolic Syndrome

Practice Questions

Pituitary Disorders

Practice Questions

Multiple Endocrine Neoplasia Syndromes

Practice Questions

Endocrine Emergencies

Practice Questions

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