Endocrinology Practice Questions

Q: A 15-year-old girl presents with short stature, neck webbing, and sexual infantilism. She is also found to have coarctation of the aorta. A chromosomal analysis is likely to demonstrate which of the following?

XO karyotype. ### Explanation **Correct Answer: C. XO karyotype** The clinical triad of **short stature, neck webbing (pterygium colli), and sexual infantilism** (due to streak ovaries/gonadal dysgenesis) in a phenotypic female is the classic presentation of **Turner Syndrome**. The presence of **coarctation of the aorta** (the most common cardiovascular malformation in Turner syndrome, occurring in ~15-20% of cases) further confirms the diagnosis. Turner syndrome is most commonly caused by **45,X monosomy** (XO karyotype), resulting from the loss of part or all of an X chromosome. **Analysis of Incorrect Options:** * **A. Mutation at chromosome 15q21.1:** This is associated with **Marfan Syndrome** (FBN1 gene). While Marfan patients have cardiac issues (aortic root dilation), they typically present with tall stature and arachnodactyly, the opposite of this patient's phenotype. * **B. Trisomy 21:** This causes **Down Syndrome**. While associated with cardiac defects (most commonly Endocardial Cushion Defects/AVSD), it presents with distinct facies, intellectual disability, and hypotonia rather than sexual infantilism and neck webbing. * **D. Defect at chromosome 4p16:** This is the locus for **Wolf-Hirschhorn Syndrome**, characterized by "Greek warrior helmet" facies, microcephaly, and severe developmental delay. **High-Yield Clinical Pearls for NEET-PG:** * **Most common cause of primary amenorrhea:** Turner Syndrome. * **Skeletal finding:** Positive **Archibald sign** (short 4th metacarpal) and Madelung deformity. * **Renal association:** **Horseshoe kidney** is the most common renal anomaly. * **Lymphedema:** Newborns often present with lymphedema of hands and feet and cystic hygroma. * **Genetics:** 50% are 45,X; others are mosaics (e.g., 45,X/46,XX) or structural abnormalities (isochromosome Xq). Mosaics have a higher risk of gonadoblastoma if a Y chromosome fragment is present.

Q: A 5-year-old child presented with abdominal distension, pallor, easy bruising, and bone pain. Physical examination revealed hepatosplenomegaly and lymphadenopathy. The child was suspected to have a metabolic disorder, and a bone marrow biopsy was planned for histopathologic examination. Microscopic examination of the stained biopsy showed a distended phagocytic cell with fibrillary cytoplasm and an eccentrically placed nucleus. Periodic acid-Schiff (PAS) staining was intensely positive. Given this presentation, what is the primary management strategy for this condition?

Replacement therapy with recombinant enzymes. **Explanation:** The clinical presentation of abdominal distension (hepatosplenomegaly), bone pain, and cytopenias (pallor, bruising) in a child, combined with the classic histopathology, points to **Gaucher Disease**, the most common lysosomal storage disorder. The "distended phagocytic cell with fibrillary cytoplasm" (often described as **"wrinkled tissue paper"** appearance) is the pathognomonic **Gaucher cell**. These are macrophages laden with glucocerebroside due to a deficiency of the enzyme **glucocerebrosidase**. The intense PAS positivity confirms the presence of complex carbohydrates/glycolipids. **Why the correct answer is right:** * **Option C (Enzyme Replacement Therapy - ERT):** This is the **gold standard** and primary management for Gaucher Disease Type 1 (the non-neuronopathic form). Recombinant enzymes (e.g., **Imiglucerase**) are administered intravenously to bypass the genetic defect, effectively reducing organomegaly and improving hematological parameters. **Why other options are incorrect:** * **Option A:** Hematopoietic stem cell transplantation (HSCT) is generally reserved for severe cases or those with neurological involvement (Type 2/3) where ERT is less effective, but it is not the first-line strategy. * **Option B:** Substrate Reduction Therapy (e.g., Miglustat) is an alternative for adults who cannot tolerate ERT, but it is not the primary treatment of choice in children. * **Option D:** Gene therapy is currently under investigation and is not yet the standard clinical management strategy. **NEET-PG High-Yield Pearls:** * **Enzyme Deficient:** Glucocerebrosidase (Acid β-glucosidase). * **Accumulated Substrate:** Glucocerebroside. * **Radiology:** Look for the **"Erlenmeyer flask deformity"** of the distal femur. * **Biomarker:** Elevated serum **Chitotriosidase** levels are used to monitor disease activity and response to therapy.

Q: What is the most common cause of delayed puberty in males?

Constitutional delay. **Explanation:** **Constitutional Delay of Growth and Puberty (CDGP)** is the most common cause of delayed puberty in both males and females, accounting for approximately 60–80% of cases. It is essentially a "late bloomer" phenomenon where the onset of puberty is delayed, but the sequence of development is normal. It is often associated with a positive family history and a characteristic delay in **bone age** compared to chronological age. These individuals eventually achieve normal adult height and full sexual maturation without intervention. **Analysis of Incorrect Options:** * **Kallmann Syndrome:** A form of hypogonadotropic hypogonadism (low FSH/LH) associated with anosmia (loss of smell). While a significant cause, it is much rarer than CDGP. * **Klinefelter Syndrome (47, XXY):** The most common cause of **primary hypogonadism** (hypergonadotropic hypogonadism). While it causes small testes and infertility, it usually presents with a normal or slightly delayed *onset* of puberty, but failure of completion. * **Prader-Willi Syndrome:** A genetic disorder (deletion on paternal chromosome 15) characterized by infantile hypotonia, hyperphagia/obesity, and hypogonadotropic hypogonadism. It is a rare syndromic cause of delayed puberty. **Clinical Pearls for NEET-PG:** * **Definition:** Delayed puberty in males is defined as the absence of testicular enlargement (**<4 mL volume** or <2.5 cm length) by **14 years** of age. * **Bone Age:** In CDGP, bone age is delayed and consistent with the height age, whereas in permanent hypogonadism, the discrepancy may be more pronounced. * **First Sign of Puberty (Males):** Testicular enlargement (due to FSH stimulating seminiferous tubules). * **Management:** Reassurance is the mainstay for CDGP. Short-term, low-dose testosterone may be used to "jumpstart" puberty if there is significant psychological distress.

Q: A 7-year-old girl presents with short stature. Examination reveals cubitus valgus, a shield-shaped chest with widely spaced nipples, a webbed neck, and a short 4th metacarpal. What is the most likely clinical diagnosis?

Turner syndrome. **Explanation:** The clinical presentation described is a classic textbook case of **Turner Syndrome (45, XO)**. This condition is the most common sex chromosome abnormality in females, characterized by the complete or partial absence of one X chromosome. **Why Turner Syndrome is correct:** The patient exhibits the hallmark phenotypic features of Turner Syndrome: * **Skeletal findings:** Short stature (most consistent feature), **cubitus valgus** (increased carrying angle of the arm), and a **short 4th metacarpal** (Archibald’s sign). * **Dermatological/Soft tissue:** **Webbed neck** (due to cystic hygroma in utero). * **Thoracic findings:** **Shield-shaped chest** with widely spaced nipples. * **Other common associations:** Bicuspid aortic valve, coarctation of the aorta, and streak ovaries leading to primary amenorrhea. **Why the other options are incorrect:** * **Klinefelter’s Syndrome (47, XXY):** Affects males. Characterized by tall stature, gynecomastia, small firm testes, and infertility. * **Edward Syndrome (Trisomy 18):** Presents with severe intellectual disability, micrognathia, low-set ears, and characteristic **clenched fists** with overlapping fingers. Most do not survive past infancy. * **Patau Syndrome (Trisomy 13):** Presents with midline defects such as cleft lip/palate, holoprosencephaly, polydactyly, and **microphthalmia**. **High-Yield Clinical Pearls for NEET-PG:** * **Most common cardiac defect:** Bicuspid aortic valve (most common overall); Coarctation of the aorta (most specific). * **Renal anomaly:** Horseshoe kidney. * **Karyotype:** 45, XO is most common (50%), but mosaicism (45,X/46,XX) carries a higher risk of gonadoblastoma if Y chromosome material is present. * **Gold Standard Diagnosis:** Chromosomal analysis (Karyotyping).

Q: Precocious puberty may be seen in all of the following conditions except:

Hyperthyroidism. **Explanation:** Precocious puberty is defined as the onset of secondary sexual characteristics before the age of 8 in girls and 9 in boys. It is categorized into **GnRH-dependent (Central)** and **GnRH-independent (Peripheral)** types. **Why Hyperthyroidism is the correct answer:** Hyperthyroidism is **not** typically associated with precocious puberty. In fact, it is **Hypothyroidism** (specifically severe, untreated primary hypothyroidism) that causes precocious puberty (Van Wyk-Grumbach Syndrome). In primary hypothyroidism, high levels of TSH can cross-react with FSH receptors due to molecular mimicry (both share a common alpha subunit), leading to follicular development and early puberty. **Analysis of other options:** * **Granulosa cell tumor:** This is a common cause of **Peripheral Precocious Puberty**. These tumors secrete estrogen directly, leading to breast development and uterine bleeding without the activation of the Hypothalamic-Pituitary-Gonadal (HPG) axis. * **Head injury:** Any CNS insult, including trauma, tumors (Hamartomas), or infections, can trigger the premature activation of the HPG axis, leading to **Central Precocious Puberty**. * **Corticosteroid intake:** Exogenous administration of steroid hormones (or accidental ingestion of estrogen-containing creams/medications) can mimic endogenous sex steroids, leading to the development of secondary sexual characteristics (Peripheral type). **High-Yield Clinical Pearls for NEET-PG:** * **McCune-Albright Syndrome:** Triad of Polyostotic fibrous dysplasia, Café-au-lait spots (Coast of Maine), and Peripheral precocious puberty. * **Most common cause of Central Precocious Puberty:** Idiopathic (80-90% in girls). * **Bone Age:** Always advanced in precocious puberty; essential for diagnosis. * **Treatment:** GnRH agonists (e.g., Leuprolide) are the gold standard for Central Precocious Puberty to prevent premature epiphyseal closure and short stature.

Q: Precocious puberty is treated by administering which of the following?

LHRH (Luteinizing Hormone-Releasing Hormone). **Explanation:** The treatment of choice for **Central Precocious Puberty (CPP)** is the administration of long-acting **GnRH (LHRH) agonists**. **Why LHRH is correct:** Under normal physiological conditions, GnRH is released from the hypothalamus in a **pulsatile** manner to stimulate the pituitary to release LH and FSH. However, when GnRH agonists (like Leuprolide or Goserelin) are administered **continuously**, they cause initial stimulation followed by a profound **down-regulation and desensitization** of the GnRH receptors on the pituitary gland. This leads to a suppression of gonadotropin (LH/FSH) secretion, effectively halting the production of sex steroids and pausing pubertal progression. **Why the other options are incorrect:** * **Testosterone (B) & Estrogen (C):** These are the very hormones responsible for the secondary sexual characteristics seen in precocious puberty. Administering them would worsen the condition and accelerate bone age maturation, leading to short adult stature. * **Gonadotrophins (D):** These (LH and FSH) directly stimulate the gonads to produce sex steroids. Administering them would further trigger pubertal development. **Clinical Pearls for NEET-PG:** * **Goal of Therapy:** The primary objectives are to stop secondary sexual development and, more importantly, to **prevent premature epiphyseal fusion** to preserve final adult height. * **Diagnosis:** CPP is confirmed by a "Pubertal" response to a GnRH stimulation test (elevated LH). * **Drug of Choice:** **Leuprolide acetate** (depot formulation) is most commonly used. * **Bone Age:** Always check bone age in these patients; it is typically advanced beyond the chronological age.

Q: A 2-year-old child presents with failure to thrive, progressive neurologic deterioration including deafness and blindness, hepatosplenomegaly, and a cherry-red spot on funduscopic examination. What is the most likely diagnosis?

Niemann-Pick disease. ### Explanation **Correct Answer: B. Niemann-Pick disease** **1. Why Niemann-Pick Disease is Correct:** Niemann-Pick disease (Type A) is a lysosomal storage disorder caused by a deficiency of **sphingomyelinase**, leading to the accumulation of sphingomyelin. The clinical triad of **progressive neurodegeneration**, **hepatosplenomegaly**, and a **cherry-red spot** on the macula is classic. While Tay-Sachs disease also presents with a cherry-red spot and neurodegeneration, the presence of **hepatosplenomegaly** is the key clinical differentiator that points specifically to Niemann-Pick. **2. Analysis of Incorrect Options:** * **A. Hunter Syndrome:** A mucopolysaccharidosis (MPS II) characterized by coarse facies, hepatosplenomegaly, and aggressive behavior. Crucially, it lacks a cherry-red spot and, unlike Hurler syndrome, does *not* have corneal clouding. * **C. Pompe’s Disease:** A glycogen storage disease (Type II) due to acid maltase deficiency. It primarily presents with severe **cardiomegaly**, hypotonia ("floppy baby"), and heart failure, but not a cherry-red spot. * **D. Tyrosinosis (Tyrosinemia Type I):** Caused by a deficiency of fumarylacetoacetate hydrolase. It presents with liver failure, rickets, and a "cabbage-like" odor, but not the neuro-ophthalmologic findings described. **3. NEET-PG High-Yield Pearls:** * **Cherry-red spot differential:** Remember the mnemonic **"SACHET"**: **S**andhoff disease, **A**maurotic familial idiocy (Tay-Sachs), **C**herry-red spot myoclonus syndrome (Sialidosis), **H**urler syndrome (rarely), **E**n central retinal artery occlusion, **T**ay-Sachs/Niemann-Pick. * **Histology:** Niemann-Pick is associated with **"Foam cells"** (lipid-laden macrophages) in the bone marrow. * **Tay-Sachs vs. Niemann-Pick:** * *Tay-Sachs:* No hepatosplenomegaly (Hexosaminidase A deficiency). * *Niemann-Pick:* Hepatosplenomegaly present (Sphingomyelinase deficiency).

Question 1

Which of the following is true regarding Turner syndrome?

Accepted Answer

Male Turner syndrome (Noonan syndrome) has a higher risk of cardiac diseases.

Answer

A webbed neck increases the risk of congenital heart disease by 10 times.

Answer

If a webbed neck is present, the aortic root is absent.

Answer

Webbing of fingers and toes is associated with visceral anomalies.

Question 2

A 15-year-old girl presents with short stature, neck webbing, and sexual infantilism. She is also found to have coarctation of the aorta. A chromosomal analysis is likely to demonstrate which of the following?

Accepted Answer

XO karyotype

Answer

Mutation at chromosome 15q21.1

Answer

Trisomy 21

Answer

Defect at chromosome 4p16

Question 3

A 5-year-old child presented with abdominal distension, pallor, easy bruising, and bone pain. Physical examination revealed hepatosplenomegaly and lymphadenopathy. The child was suspected to have a metabolic disorder, and a bone marrow biopsy was planned for histopathologic examination. Microscopic examination of the stained biopsy showed a distended phagocytic cell with fibrillary cytoplasm and an eccentrically placed nucleus. Periodic acid-Schiff (PAS) staining was intensely positive. Given this presentation, what is the primary management strategy for this condition?

Accepted Answer

Replacement therapy with recombinant enzymes

Answer

Allogenic hematopoietic stem cell transplantation

Answer

Substrate reduction therapy

Answer

Transfer of normal gene into the patient's hematopoietic stem cells

Question 4

What is the most common cause of delayed puberty in males?

Accepted Answer

Constitutional delay

Answer

Kallmann syndrome

Answer

Klinefelter syndrome

Answer

Prader-Willi syndrome

Question 5

A 2-year-old child presented with diarrhea and failure to thrive. Blood examination shows Na = 122 mEq/L, K = 6 mEq/L. The child is most probably suffering from which of the following conditions?

Accepted Answer

21-hydroxylase deficiency

Answer

Bartter syndrome

Answer

11-β-hydroxylase deficiency

Answer

17-α-hydroxylase deficiency

Question 6

Clinical manifestations of hoarse cry, umbilical hernia, hypotonia, mottling of skin, and lethargy, with prolonged jaundice, are seen in which condition?

Accepted Answer

Congenital hypothyroidism

Answer

Gaucher's disease

Answer

Mucopolysaccharidosis

Answer

Growth hormone deficiency

Question 7

A 7-year-old girl presents with short stature. Examination reveals cubitus valgus, a shield-shaped chest with widely spaced nipples, a webbed neck, and a short 4th metacarpal. What is the most likely clinical diagnosis?

Accepted Answer

Turner syndrome

Answer

Klinefelter's syndrome

Answer

Edward Syndrome

Answer

Patau syndrome

Question 8

Precocious puberty may be seen in all of the following conditions except:

Accepted Answer

Hyperthyroidism

Answer

Granulosa cell tumor

Answer

Head injury

Answer

Corticosteroid intake

Question 9

Precocious puberty is treated by administering which of the following?

Accepted Answer

LHRH (Luteinizing Hormone-Releasing Hormone)

Answer

Testosterone

Answer

Estrogen

Answer

Gonadotrophin

Question 10

A 2-year-old child presents with failure to thrive, progressive neurologic deterioration including deafness and blindness, hepatosplenomegaly, and a cherry-red spot on funduscopic examination. What is the most likely diagnosis?

Accepted Answer

Niemann-Pick disease

Answer

Hunter syndrome

Answer

Pompe's disease

Answer

Tyrosinosis

Endocrinology — MCQs

Endocrinology — MCQs

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