Endocrinology Practice Questions

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

< 54 mg/dL. ***< 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.

Q: A 6-year-old girl presents with precocious puberty, some bony lesions & hyperpigmented skin lesions as shown below. What is the most probable diagnosis?

McCune-Albright syndrome. ***McCune-Albright syndrome*** - This syndrome is characterized by the classic triad of **precocious puberty**, **polyostotic fibrous dysplasia** (bony lesions), and **café-au-lait spots** (hyperpigmented skin lesions). - The combination of these specific symptoms in a 6-year-old girl is highly indicative of McCune-Albright syndrome. *Cushing syndrome* - Characterized by signs of **hypercortisolism**, such as truncal obesity, moon facies, buffalo hump, and striae. - While it can cause some skin changes, it does not typically present with the specific bony lesions or precocious puberty seen here. *Laurence Moon syndrome* - A rare genetic disorder characterized by **retinitis pigmentosa**, mental retardation, spastic paraplegia, and pituitary dysfunction, often including hypogonadism. - It does not present with fibrous dysplasia, hyperpigmented skin lesions, or precocious puberty as the primary manifestation. *Prader Willi syndrome* - Characterized by **obesity**, **hypotonia** in infancy, developmental delay, and hypogonadism. - It does not involve precocious puberty, fibrous dysplasia, or café-au-lait spots.

Q: 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 –

Diabetes insipidus. ***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.

Q: Which is false in Congenital Hypopituitarism?

Baby small at birth. ***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**.

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

25 – 50%. ***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.

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

Turner syndrome. ***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.

Q: The commonest cause of congenital hypothyroidism is -

Thyroid dysgenesis. ***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.

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

Mental retardation. ***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 1

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

Accepted Answer

< 54 mg/dL

Answer

< 40 mg/dL

Answer

< 50 mg/dL

Answer

< 45 mg/dL

Question 2

A 6-year-old girl presents with precocious puberty, some bony lesions & hyperpigmented skin lesions as shown below. What is the most probable diagnosis?

Accepted Answer

McCune-Albright syndrome

Answer

Cushing syndrome

Answer

Laurence Moon syndrome

Answer

Prader Willi syndrome

Question 3

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 –

Accepted Answer

Diabetes insipidus

Answer

Barter's syndrome

Answer

Recurrent UTI

Answer

Renal tubular acidosis

Question 4

Which is false in Congenital Hypopituitarism?

Accepted Answer

Baby small at birth

Answer

Hypoglycemia

Answer

Growth hormone level < 7 ng/ml

Answer

Delayed puberty

Question 5

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

Accepted Answer

25 – 50%

Answer

50 – 75%

Answer

0 – 25%

Answer

75 – 100%

Question 6

A 6-year-old girl presents with a left breast mass. Her mother first noticed it a day before and is very concerned because both the child's maternal grandmother and maternal aunt have had breast cancer. It is firm, smoothly circumscribed, and slightly eccentric under the left areola. The right breast is unremarkable. You suggest:

Accepted Answer

Repeat examination in 1 month

Answer

Genetic testing for breast cancer (BRCA) 1 and 2 mutations

Answer

Immediate excisional biopsy

Answer

A mammogram

Question 7

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

Accepted Answer

Turner syndrome

Answer

Granulosa cell tumor of the ovary

Answer

McCune-Albright syndrome

Answer

Hypothalamic hamartoma

Question 8

The commonest cause of congenital hypothyroidism is -

Accepted Answer

Thyroid dysgenesis

Answer

Pendred syndrome

Answer

Deficiency of deiodinase

Answer

Defective release

Question 9

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

Accepted Answer

3,4,5 True & 1,2 False

Answer

1,2,3 False & 4,5 True

Answer

1,2,3 True & 4,5 False

Answer

1,4,5 True & 2,3 False

Question 10

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

Accepted Answer

Mental retardation

Answer

Large tongue

Answer

Large posterior fontanel

Answer

Sluggishness +++

Endocrinology — MCQs

Endocrinology — MCQs

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