While evaluating a 3-year-old with short stature, height is measured at 90cm and the lower segment is 45 cm. What is the likely diagnosis?
A child presents with micrognathia and low-set ears. These clinical features are commonly associated with which type of genetic abnormality?
A child presents with a right transverse palmar crease, a cardiac defect, survival into childhood, and mild intellectual impairment. What chromosomal mechanism is most likely associated with these findings?
A girl presents with microcephaly and a high-pitched cry. Which of the following is the most likely chromosomal abnormality?
A child presents with recurrent Staphylococcus infections. Laboratory examination shows very low levels of immunoglobulins (G, A, M, E), and a low quantity of B cells. There is a normal reaction to environmental antigens on the skin. What is the most likely diagnosis?
What is the recommended treatment for nephrotic syndrome in children?
In a child presenting with a beaded appearance in the chest with the following X-ray, what is the diagnosis? 
A newborn male presents with urinary retention, lethargy and a distended bladder. Antenatal ultrasound showed a "keyhole sign" with a thickened bladder wall. Which of the following is the most likely diagnosis?
A child with progressive pallor and bone pain has an elevated HbS based on the HPLC report. Which is the best treatment to manage hemolysis in this patient?
A child presents with kawasaki disease with multiple small coronary artery aneurysms. Treatment is?
FMGE 2025 - Pediatrics FMGE Practice Questions and MCQs
Question 21: While evaluating a 3-year-old with short stature, height is measured at 90cm and the lower segment is 45 cm. What is the likely diagnosis?
- A. Congenital hypothyroidism
- B. Rickets
- C. Spondyloepiphyseal dysplasia (Correct Answer)
- D. Achondroplasia
Explanation: ***Spondyloepiphyseal dysplasia*** - This child has an **upper:lower segment ratio of 1:1** (45 cm each), which indicates **adult body proportions at age 3** - Normal U:L ratio at 3 years should be approximately **1.3:1** (relatively longer trunk than legs) - Spondyloepiphyseal dysplasia causes **short trunk dwarfism** due to vertebral and epiphyseal involvement - The **limbs are relatively preserved**, leading to a **lower U:L ratio** than expected for age (approaching adult 1:1 ratio prematurely) - This creates **disproportionate short stature** with the trunk being the primary affected segment *Congenital hypothyroidism* - Causes **proportionate short stature** with generalized growth retardation - Would maintain normal U:L ratio for age (1.3:1 at 3 years) - Associated with delayed bone age, developmental delay, and other systemic features *Rickets* - Primarily affects the **lower limbs** with bowing deformities (genu varum/valgum) - Would cause a **higher U:L ratio** (relatively shorter legs) if severe - Does not typically present with this specific 1:1 ratio pattern *Achondroplasia* - Causes **short limb dwarfism** (rhizomelic shortening) - Would result in a **high U:L ratio** (relatively longer trunk than limbs) - Opposite pattern to what is seen in this case
Question 22: A child presents with micrognathia and low-set ears. These clinical features are commonly associated with which type of genetic abnormality?
- A. Amplification
- B. Inversion
- C. Translocation
- D. Deletion (Correct Answer)
Explanation: ***Correct: Deletion*** - **Micrognathia** and **low-set ears** are characteristic features of many syndromes caused by chromosomal deletions, such as **DiGeorge syndrome** (22q11.2 deletion) or **Cri-du-chat syndrome** (5p deletion). - The loss of a significant segment of a chromosome leads to **haploinsufficiency** for multiple genes, severely impacting craniofacial and auricular development. *Incorrect: Translocation* - This involves the exchange of segments between non-homologous chromosomes; while it can cause genetic disorders, it is not the most common genetic mechanism leading to the specific classic combination of micrognathia and low-set ears. - **Balanced translocations** usually do not cause clinical symptoms in the carrier, but can lead to abnormal gametes and offspring with partial monosomy or trisomy. *Incorrect: Amplification* - This refers to the increase in the copy number of a gene or DNA sequence, which is primarily linked to cancer development (**oncogenesis**, e.g., *HER2* amplification), not generalized congenital dysmorphism. - While large segmental duplications (a form of gain) can cause syndromes, specific amplification events are rarely the cause of micrognathia or low-set ears. *Incorrect: Inversion* - This involves a chromosomal segment reversing its orientation; the primary concern is the formation of **unbalanced gametes** during meiosis, particularly with **pericentric inversions**. - Although offspring can inherit unbalanced chromosomes resulting in abnormalities, deletions remain the most common cause for the specific constellation of features mentioned.
Question 23: A child presents with a right transverse palmar crease, a cardiac defect, survival into childhood, and mild intellectual impairment. What chromosomal mechanism is most likely associated with these findings?
- A. Mosaicism (Correct Answer)
- B. Haploid
- C. Monosomy
- D. Trisomy
Explanation: ***Mosaicism*** - **Mosaicism** is the presence of two or more cell lines with different genetic constitutions in a single individual, allowing for a **milder phenotype** of chromosomal syndromes like Trisomy 21. - The combination of classic Down syndrome features (transverse palmar crease, cardiac defect) with relatively **mild intellectual impairment** and survival into childhood with better outcomes suggests **Mosaic Down Syndrome** (mosaic Trisomy 21). - In mosaicism, only a proportion of cells carry the extra chromosome 21, resulting in **less severe manifestations** compared to complete trisomy. *Incorrect: Trisomy* - While **complete Trisomy 21** (Down syndrome) presents with similar features, it typically causes **more severe intellectual disability** and greater phenotypic expression. - The emphasis on **"mild" intellectual impairment** in this case points toward mosaicism rather than complete trisomy. *Incorrect: Haploid* - **Haploid** refers to a cell having only one set of chromosomes (n=23), a state that is **incompatible with human survival** beyond early embryonic development. - A complete haploid individual cannot survive into **childhood**. *Incorrect: Monosomy* - **Monosomy** (loss of one chromosome, 2n-1) for autosomes is typically **lethal in utero**, making survival into childhood impossible. - The only viable monosomy is **Monosomy X** (Turner syndrome), which presents with distinct features (short stature, webbed neck, ovarian dysgenesis) without the characteristic Down syndrome features described.
Question 24: A girl presents with microcephaly and a high-pitched cry. Which of the following is the most likely chromosomal abnormality?
- A. Mosaicism
- B. Trisomy
- C. Isochromosome
- D. Deletion (Correct Answer)
Explanation: ***Deletion***- The combination of **microcephaly** and a peculiar **high-pitched cry** (often described as 'cat-like') is the hallmark clinical presentation of **Cri-du-chat syndrome**.- Cri-du-chat syndrome is caused by a **deletion** of the distal part of the short arm of chromosome 5 (5p-).*Isochromosome*- An **isochromosome** is a structural chromosomal abnormality where an arm is duplicated, resulting in two copies of one arm and none of the other (e.g., often seen in X chromosome abnormalities like **Turner syndrome**).- This type of structural error does not typically result in the specific features of Cri-du-chat syndrome, which require the loss of specific genes on **chromosome 5 short arm**.*Trisomy*- **Trisomy** is the presence of an extra copy of a chromosome (47 total chromosomes, e.g., **Down syndrome - Trisomy 21**).- Syndromes resulting from autosomal trisomies (like Patau or Edwards) present with different constellations of congenital and developmental abnormalities, lacking the pathognomonic **cat-like cry**.*Mosaicism*- **Mosaicism** describes the presence of two or more populations of cells with different genotypes in one individual, often mitigating the severity of major aneuploidies.- While it can occur with some deletions, **mosaicism** is not the primary mechanism or classification for the specific **Cri-du-chat syndrome** which is defined by the **5p deletion**.
Question 25: A child presents with recurrent Staphylococcus infections. Laboratory examination shows very low levels of immunoglobulins (G, A, M, E), and a low quantity of B cells. There is a normal reaction to environmental antigens on the skin. What is the most likely diagnosis?
- A. Common variable immunodeficiency
- B. Hyper IgM syndrome
- C. DiGeorge syndrome
- D. Bruton's agammaglobulinemia (Correct Answer)
Explanation: ***Bruton's agammaglobulinemia***- This X-linked disease is caused by a defect in the **Bruton tyrosine kinase (BTK)** gene, which is essential for B-cell maturation.- The deficiency results in a severe block in B-cell development, leading to **near absence of mature B cells** and consequently, extremely **low levels of all immunoglobulin isotypes** (IgG, A, M, E).*DiGeorge syndrome*- Primary feature is **T-cell deficiency** due to failure of the 3rd and 4th pharyngeal pouches, leading to **thymic hypoplasia**; this would typically impair the skin test response. - Although B cell numbers can sometimes be affected, the hallmark is severe T-cell deficiency, and Ig levels are often normal or near-normal, unlike the pan-hypogammaglobulinemia seen here.*Hyper IgM syndrome*- This condition is characterized by a failure in **isotype switching** (often due to defects in **CD40L**), resulting in normal or high levels of **IgM** but very low levels of IgG, IgA, and IgE.- B cells are present in normal counts, distinguishing it from this patient who has very few B cells and very low IgM.*Common variable immunodeficiency*- CVID typically presents later, in adolescence or adulthood, and causes **hypogammaglobulinemia** (low IgG and usually low IgA/IgM).- While B-cell function is impaired, patients usually have **normal B-cell counts**, contrasting with the severe reduction in B cells seen in this child.
Question 26: What is the recommended treatment for nephrotic syndrome in children?
- A. ACE inhibitors
- B. Cyclophosphamide
- C. Steroids and cyclophosphamide
- D. Steroids (Correct Answer)
Explanation: ***Steroids***- **Corticosteroids** (typically Prednisone/Prednisolone) are the recommended **first-line therapy** for pediatric nephrotic syndrome, as *minimal change disease* (**MCD**) is the most common cause (90% of cases).- The vast majority of children with MCD are **steroid-sensitive**, exhibiting remission (proteinuria cessation) within 2-4 weeks of high-dose treatment.*Steroids and cyclophosphamide*- Combination therapy including **cyclophosphamide** is typically reserved for children who show **steroid dependence** or **frequent relapses**, not for initial therapy.- Adding cyclophosphamide as a first-line agent is unnecessary due to its potential for significant **gonadal toxicity** and other systemic side effects.*Cyclophosphamide*- **Cyclophosphamide** is a powerful **second-line immunosuppressive agent** used primarily for children who are steroid-dependent or **steroid-resistant**.- Using it as initial monotherapy is inappropriate because children with MCD usually respond well to steroids alone, avoiding risks like **myelosuppression**.*ACE inhibitors*- **Angiotensin-converting enzyme (ACE) inhibitors** are used primarily to reduce **proteinuria** by lowering **glomerular hydrostatic pressure**.- Their role is generally adjunctive management for resistant proteinuria or for treating associated **hypertension**, not as the primary agent to induce remission.
Question 27: In a child presenting with a beaded appearance in the chest with the following X-ray, what is the diagnosis? 
- A. Beri Beri
- B. Pellagra
- C. Rickets (Correct Answer)
- D. Scurvy
Explanation: ***Rickets*** - The clinical finding of a "beaded appearance" in the chest refers to **rachitic rosary**, which is a classic sign of rickets caused by the enlargement of the costochondral junctions. - The wrist X-ray confirms the diagnosis by showing characteristic features of defective bone mineralization, including **cupping**, **fraying**, and widening of the distal metaphysis of the radius and ulna. *Scurvy* - Scurvy, caused by **vitamin C deficiency**, typically presents with **bleeding gums**, poor wound healing, and perifollicular hemorrhage, not skeletal deformities like a rachitic rosary. - Radiographic findings in scurvy include a **white line of Fraenkel** (a dense metaphyseal line) and subperiosteal hemorrhages, which are absent in the provided X-ray. *Beri Beri* - Beri Beri is a result of **thiamine (vitamin B1) deficiency** and primarily manifests with neurological (dry beriberi) or cardiovascular (wet beriberi) symptoms. - This condition does not cause the characteristic skeletal abnormalities or radiographic changes seen in rickets. *Pellagra* - Pellagra is caused by **niacin (vitamin B3) deficiency** and is characterized by the classic triad of **dermatitis**, **diarrhea**, and **dementia** (the "3 Ds"). - It is a systemic illness that does not involve the skeletal system in the manner described or shown in the X-ray.
Question 28: A newborn male presents with urinary retention, lethargy and a distended bladder. Antenatal ultrasound showed a "keyhole sign" with a thickened bladder wall. Which of the following is the most likely diagnosis?
- A. Posterior urethral valves (Correct Answer)
- B. Hypospadias
- C. Vesicoureteral reflux
- D. Neurogenic bladder
Explanation: ***Posterior urethral valves***- The **"keyhole sign"** seen on antenatal ultrasound, characterized by a dilated posterior urethra and a thickened, distended bladder, is highly specific for **posterior urethral valves (PUV)**.- PUV is the most common cause of severe **lower urinary tract obstruction** in male newborns, leading directly to symptoms like lethargy, a palpable **distended bladder**, and urinary retention.*Hypospadias*- *Hypospadias* is an abnormal location of the **urethral meatus** on the ventral aspect of the penis.- It does not cause the severe **obstructive uropathy** (like urinary retention and bladder distension) or the **keyhole sign** observed in this patient.*Vesicoureteral reflux*- *Vesicoureteral reflux* (VUR) involves the reflux of urine from the bladder back up to the ureters and is typically a **non-obstructive** cause of hydronephrosis and UTIs.- While VUR can coexist with PUV, it is the secondary phenomenon, and VUR itself does not cause the primary **urethral obstruction** or the characteristic **keyhole appearance**.*Neurogenic bladder*- A *neurogenic bladder* results from impaired nerve supply, often due to conditions like **spina bifida**, leading to poor bladder emptying.- While it can cause retention, the unique finding of the **keyhole sign** points specifically to a fixed, **anatomical obstruction** in the posterior urethra, which is not characteristic of neurological issues.
Question 29: A child with progressive pallor and bone pain has an elevated HbS based on the HPLC report. Which is the best treatment to manage hemolysis in this patient?
- A. Azacytidine
- B. Hydroxyurea
- C. Bortezomib
- D. Voxelotor (Correct Answer)
Explanation: ***Voxelotor*** - It is a **hemoglobin polymerization inhibitor** that stabilizes the oxygenated form of red blood cells, preventing **sickling** and subsequent hemolytic anemia, thereby directly managing the hemolysis. - It significantly improves **hemoglobin levels** and reduces markers of hemolysis, such as **indirect bilirubin** and **reticulocyte count**. *Hydroxyurea* - Its primary mechanism is inducing the production of **fetal hemoglobin (HbF)**, thereby diluting the concentration of HbS and *indirectly* reducing hemolysis over time. - Although crucial for managing **vaso-occlusive crises** (VOCs), it is not as direct an anti-hemolytic agent as Voxelotor. *Azacytidine* - This is a **DNA methyltransferase inhibitor**, primarily used in high-risk **Myelodysplastic Syndrome (MDS)** and Acute Myeloid Leukemia (AML). - While it can induce HbF like Hydroxyurea, it is not a standard or approved frontline treatment for the routine management of Sickle Cell Disease (SCD). *Bortezomib* - This drug is a **proteasome inhibitor** used exclusively in the treatment of **Multiple Myeloma** and certain related plasma cell dyscrasias. - It has no therapeutic role or clinical indication in the specific management of hemolysis or the underlying pathophysiology of SCD.
Question 30: A child presents with kawasaki disease with multiple small coronary artery aneurysms. Treatment is?
- A. Aspirin for 6 weeks (Correct Answer)
- B. Aspirin for 4 weeks
- C. Aspirin lifelong
- D. Aspirin and clopidogrel for 6 weeks
Explanation: ***Aspirin for 6 weeks*** - After the acute phase is treated with **IVIG** and high-dose aspirin, the regimen is switched to low-dose aspirin for its **antiplatelet** effects to prevent thrombosis in the affected coronary arteries. - This low-dose therapy is typically continued for 6-8 weeks, at which point a follow-up **echocardiogram** is performed and inflammatory markers (like **ESR** and **CRP**) should have normalized. *Aspirin lifelong* - Lifelong antiplatelet therapy is generally reserved for patients with **large** or **giant** coronary artery aneurysms due to a high risk of **thrombosis** and stenosis. - For small aneurysms, which often resolve, therapy is guided by serial echocardiograms and is not typically lifelong from the outset. *Aspirin for 4 weeks* - A 4-week duration is insufficient, as it may not cover the entire period of coronary wall inflammation and thrombocytosis, which usually peaks in the subacute phase. - The standard follow-up interval for re-evaluation with an **echocardiogram** is at 6-8 weeks, making it logical to continue therapy at least until that point. *Aspirin and clopidogrel for 6 weeks* - **Dual antiplatelet therapy** with aspirin and clopidogrel is recommended for patients with **medium-sized** or **giant** coronary artery aneurysms, not for small aneurysms. - The flowchart provided indicates that for small aneurysms (Z score ≥2.5 to <5), **single antiplatelet therapy** with low-dose aspirin is the appropriate treatment.