Paediatrics and Genetics Y2 MCQs

Question 1: A 5-month-old infant is exclusively formula-fed. The parents ask if they can start weaning now. Which of the following is the most appropriate response based on WHO and UK guidance?

A) Weaning should never begin before 12 months to reduce allergy risk
B) Weaning should begin at birth alongside formula
C) Weaning may begin around 6 months, even if the infant is formula-fed
D) Weaning should start at 3 months to reduce the risk of celiac disease
E) Weaning is not needed in formula-fed infants

Question 2: You are reviewing the growth chart of a 10-month-old boy. His weight has dropped from the 50th to the 9th centile over 2 months, while his length and head circumference remain on the 50th centile. What is the most appropriate interpretation?

A) Likely normal growth pattern due to genetic short stature
B) This is expected during the weaning period
C) Consistent with premature growth pattern
D) Indicates catch-down growth and is reassuring
E) Suggests acute malnutrition or feeding problem

Question 3: A 4-month-old infant was born at 28 weeks gestation. When plotting weight on the UK-WHO growth chart, how should age be adjusted?

A) Plot weight at actual age of 4 months
B) Plot weight 12 weeks earlier to account for corrected gestational age
C) Use the standard chart without correction since baby is past term
D) Use a separate preterm growth chart until age 12
E) Do not plot until the infant reaches 6 months corrected age

Question 4: A mother asks why breastfeeding is recommended over formula for the first 6 months. Which of the following best describes the primary advantage?

A) Breast milk causes faster infant weight gain than formula
B) It prevents all genetic conditions such
C) It delays teething and thus improves dental health
D) It provides complete nutrition and immune protection
E) Formula causes lactose intolerance in most infants

Question 5: A 3-year-old child has BMI plotted on the 98th centile of the child BMI chart. His weight is on the 99th centile, height on the 75th centile. What is the best interpretation?

A) Child has stunted growth and requires growth hormone
B) Likely to develop short stature due to high BMI
C) This BMI should be interpreted using adult cutoffs
D) Child is overweight based on age- and sex-specific BMI chart
E) Normal growth due to proportional centile differences

Question 6: A healthy 6-month-old infant begins weaning. What is the most appropriate starting consistency of food? 

A) Whole cooked vegetables
B) Smooth pureed food
C) Chopped adult meals
D) Cow’s milk as main drink
E) Raw protein sources

Question 7: A baby is introduced to solid food at 8 weeks of age. What is the major risk of this early introduction? 

A) Increased allergy and infection risk
B) Reduced fat absorption
C) Delayed neurodevelopment
D) Hypercalcaemia
E) Poor sleep

Question 8: A 6-week-old male infant presents with choking and cyanosis during feeds, along with recurrent aspiration pneumonia. A nasogastric tube coil is seen in the upper oesophagus on X-ray. What is the most likely diagnosis? 

A) Laryngomalacia
B) Pyloric stenosis
C) Choanal atresia
D) Laryngeal cleft
E) Tracheoesophageal fistula with oesophageal atresia

Question 9: A newborn has scaphoid abdomen, respiratory distress, and mediastinal shift. What is the most likely diagnosis? 

A) Tracheomalacia
B) Bronchopulmonary dysplasia
C) Congenital diaphragmatic hernia
D) Tracheoesophageal fistula with atresia
E) Meconium aspiration syndrome 

Question 10: Which of the following chromosomal abnormalities is associated with duodenal atresia? 

A) Trisomy 13
B) Trisomy 18
C) Trisomy 21
D) Monosomy X
E) Triploidy 

Question 11:What is the formula for calculating mid-parental height for a male child?
A) (Mother’s height + Father’s height) / 2
B) (Mother’s height + Father’s height ±13 cm) / 2
C) (Mother’s height – 13 cm + Father’s height) / 2
D) (Mother’s height + Father’s height – 13 cm) / 2
E) (Mother’s height + 13 cm + Father’s height) / 2

Question 12: Which of the following is a key clinical feature of Turner syndrome?
A) Macrocephaly
B) Widely spaced nipples and webbed neck
C) Hyperthyroidism
D) Accelerated growth velocity
E) Early puberty

Question 13: Which hormone is critical for the pubertal growth spurt?
A) Growth hormone (GH)
B) Thyroxine
C) Insulin
D) Cortisol
E) Parathyroid hormone

Question 14: A child born small for gestational age (SGA) without catch-up growth by age 4 should be evaluated for:
A) Familial short stature
B) Marfan syndrome
C) Hyperthyroidism
D) Growth hormone deficiency
E) Precocious puberty

Question 15: Which genetic test is MOST appropriate for a child with dysmorphic facial features, congenital heart defects, and developmental delay?
A) Karyotyping
B) Chromosome Microarray Analysis (CMA)
C) Haemoglobin Electrophoresis
D) Sweat Test
E) Trisomy FISH Test

Question 16: A neonate presents with cyanosis, Tetralogy of Fallot, and hypocalcaemia. Which syndrome is MOST likely?
A) Down Syndrome (Trisomy 21)
B) VACTERL Association
C) Turner Syndrome
D) CHARGE Syndrome
E) DiGeorge Syndrome (22q11 Deletion)

Question 17: Which finding is part of the Potter Sequence?
A) Coloboma
B) Choanal Atresia
C) Thymic Aplasia
D) Pulmonary Hypoplasia
E) Macrocephaly

Question 18: A family history shows early-onset breast cancer in multiple generations. Which genetic test is MOST appropriate?
A) Whole Exome Sequencing (WES)
B) Targeted BRCA1/2 Panel
C) Chromosome Microarray (CMA)
D) Karyotyping
E) Mitochondrial DNA Analysis

Question 19: A “Variant of Uncertain Significance (VUS)” is classified as which class in pathogenicity grading?
A) Class 1
B) Class 2
C) Class 3
D) Class 4
E) Class 5

Question 20: A neonate with tracheoesophageal fistula (TEF) and unilateral radial aplasia is found to have hemivertebrae. Chromosome microarray is normal. Which genetic testing approach is MOST appropriate next?
A) Whole Genome Sequencing (WGS) trio (proband + parents)
B) CHD7 gene sequencing
C) FISH testing
D) Mitochondrial genome analysis
E) BRCA1/2 testing

Question 21: Osteogenesis imperfecta is caused by mutations in which protein?
A) Fibrillin-1
B) Collagen
C) Dystrophin
D) Keratin
E) Elastin

Question 22: Which condition is characterized by severe congenital heart defects, holoprosencephaly, and polydactyly?

A) Down syndrome
B) Edwards syndrome
C) Patau syndrome
D) Turner syndrome
E) DiGeorge syndrome

Question 23: A newborn presenting with bilious vomiting should urgently be evaluated for:

A) Meconium aspiration
B) Malrotation with volvulus
C) Cystic fibrosis
D) Tracheoesophageal fistula
E) Patent ductus arteriosus

Question 24: In congenital diaphragmatic hernia, what finding worsens prognosis?

A) Hernia on left side
B) Small head circumference
C) No liver involvement
D) Absence of polyhydramnios
E) Hernia on right side

Question 25: A neonate has rocker-bottom feet, clenched fists, and severe congenital heart defects. What is the likely diagnosis?

A) Down syndrome
B) Patau syndrome
C) Edwards syndrome
D) Turner syndrome
E) Noonan syndrome

Question 26: What best describes a single nucleotide polymorphism (SNP)?

A) A large chromosomal deletion
B) A copy number variant
C) A balanced translocation
D) A change in a single DNA base
E) A mitochondrial mutation

Question 27: A 4-month-old infant bats at a dangling toy but cannot grasp it. Which developmental domain is primarily assessed?
A) Gross motor
B) Fine motor
C) Language
D) Social-emotional
E) Cognitive

Question 28: Which reflex disappears by 4-6 months and is abnormal if persistent?
A) Moro reflex
B) Parachute reflex
C) Babinski reflex
D) Licking reflex
E) Trunk incurvation

Question 29: A 3-week-old infant is exclusively breastfed. The mother is concerned about whether breastfeeding alone is sufficient for her baby’s growth and long-term health. Based on WHO guidelines and the known physiological effects of breastfeeding, which of the following statements is most accurate?

A) Breastfeeding alone until 6 months decreases the infant’s risk of Type II Diabetes but has no impact on cardiovascular disease risk later in life.
B) Breastfeeding provides passive immunity to the infant primarily through the transfer of maternal immunoglobulin G (IgG) in the breast milk.
C) Exclusive breastfeeding significantly reduces the incidence of necrotising enterocolitis (NEC) in neonates, particularly in preterm infants.
D) Breastfeeding rates in the UK show that over 70% of babies are still breastfed at 6–8 weeks postpartum.
E) The protective benefits of breastfeeding on maternal breast cancer risk are only observed if breastfeeding is continued beyond 2 years.

Question 30: A 5-month-old infant is brought to clinic for a routine check-up. The parents are keen to start weaning early because their baby seems interested in their food. Based on best practice guidelines, which of the following is the most appropriate advice to give the parents?

A) Begin feeding mashed food immediately, as the infant’s kidneys and gut are fully mature by 5 months.
B) It is safe to start weaning at 5 months because early exposure to foods will reduce allergy risk.
C) Delay weaning until around 6 months, when developmental milestones like head control and swallowing are achieved.
D) Introduce chopped-up adult food immediately after starting weaning to encourage quicker adaptation.
E) Encourage a low-fat diet once weaning begins to promote healthy weight maintenance.

Question 31: A newborn is diagnosed with a genetic abnormality after routine screening. Genetic testing reveals an extra copy of chromosome 21. Which of the following best describes this chromosomal abnormality?

A) Structural abnormality: reciprocal translocation
B) Structural abnormality: deletion
C) Numerical abnormality: trisomy
D) Numerical abnormality: monosomy
E) Numerical abnormality: triploidy

Question 32: A newborn presents with severe hypotonia, congenital heart defects, and dysmorphic facial features. Genetic analysis reveals that the child has 46 chromosomes, but fluorescence in situ hybridisation (FISH) identifies a translocation involving chromosome 21 material onto chromosome 14, with an unbalanced gain of chromosome 21 material. Which of the following best explains the underlying genetic mechanism?

A) Numerical abnormality: aneuploidy, trisomy 21 from non-disjunction
B) Structural abnormality: Robertsonian unbalanced translocation involving an acrocentric chromosome
C) Structural abnormality: reciprocal balanced translocation
D) Numerical abnormality: triploidy
E) Structural abnormality: deletion on chromosome 14

Question 33: A newborn girl is delivered at term with multiple congenital anomalies, including cleft lip and palate, polydactyly, severe intellectual disability, and cardiac defects. Cytogenetic analysis shows 47 chromosomes, including an extra chromosome. Which of the following diagnoses is most consistent with these findings?

A) Edwards Syndrome (Trisomy 18)
B) Turner Syndrome (45, X)
C) Patau Syndrome (Trisomy 13)
D) Klinefelter Syndrome (47, XXY)
E) Triple X Syndrome (47, XXX)

Question 34: A 5-year-old child is referred to genetics after exhibiting developmental delay and dysmorphic features consistent with a suspected chromosomal abnormality. Cytogenetic testing is requested to identify possible deletions or duplications in the patient’s genome. Which of the following genetic testing methods is most appropriate to detect small-scale duplications or deletions in the genome?

A) FISH with a probe for chromosome 21
B) Multicoloured FISH + Microarray Analysis
C) Next Generation Sequencing (NGS)
D) Genome-Wide Association Study (GWAS)
E) Karyotyping

Question 35: A researcher is studying a genetic mutation in a patient that involves an insertion of a single base pair into a gene. The mutation is located after the initial start codon but before the first stop codon. Which of the following is the most likely outcome of this mutation?

A) A truncated protein will be produced due to a premature stop codon.
B) The entire amino acid sequence after the mutation will be altered, and the protein may be non-functional.
C) The amino acid sequence will remain unchanged, but the protein will have an altered structure.
D) The gene will undergo silent mutation, with no effect on the protein.
E) The mutation will cause no effect on the gene, as only one base pair is inserted.

Question 36: A woman who is a carrier of Duchenne’s Muscular Dystrophy (DMD) (X-linked recessive) has a son who is unaffected by the disease. She is considering having another child with her partner, who is unaffected. Which of the following is the most likely genetic risk for their next child?

A) The next son will have a 25% chance of being affected by DMD.
B) The next daughter will have a 50% chance of being a carrier of DMD.
C) The next son will have a 50% chance of being a carrier of DMD.
D) The next daughter will have a 25% chance of being affected by DMD.
E) The next child, regardless of gender, will have a 50% chance of being a carrier of DMD.

Question 37: A 2-year-old child is diagnosed with Prader-Willi syndrome after presenting with hypotonia, insatiable hunger, and delayed milestones. Genetic testing reveals a deletion of a region on chromosome 15, and methylation studies confirm the loss of the paternal contribution in the affected region. Which of the following statements best explains the mechanism behind the development of Prader-Willi syndrome?

A) The child inherited two copies of chromosome 15 from the mother, resulting in a complete lack of the paternal contribution, which is required for normal development.
B) The methylation of the maternal allele in the region of chromosome 15 leads to silencing of the gene, resulting in loss of function of important genes, which causes the syndrome.
C) The condition arises when a deletion of the paternal allele occurs due to a failure of X-inactivation during early development, leading to an imbalanced gene expression.
D) The loss of paternal gene expression occurs due to methylation or deletion of a specific region on chromosome 15, and since the maternal allele is silenced, the child has no functional copy of the gene.
E) In Prader-Willi syndrome, the paternal allele is lost through a methylation event, and the resulting failure to express maternal alleles leads to the typical symptoms of the syndrome.

Question 38: A neonate is diagnosed with tracheoesophageal fistula (TEF) and is undergoing genetic testing. The following conditions are associated with the development of TEF in this infant. Which of the following sets of conditions are correctly associated with TEF?

A) Trisomy 13 (Patau’s Syndrome), Trisomy 18 (Edwards Syndrome), VACTERL association, and Holt-Oram Syndrome
B) Trisomy 13 (Patau’s Syndrome), Trisomy 21 (Down syndrome), VACTERL association, and Cystic Fibrosis
C) Trisomy 18 (Edwards Syndrome), VACTERL association, DiGeorge Syndrome, and Duchenne Muscular Dystrophy
D) Trisomy 13 (Patau’s Syndrome), Trisomy 18 (Edwards Syndrome), VACTERL association, and CHARGE Syndrome
E) Trisomy 21 (Down syndrome), DiGeorge Syndrome, VACTERL association, and Beckwith-Wiedemann Syndrome

Question 39: A 1-day-old term neonate presents with progressive abdominal distension, intermittent irritability, and repeated episodes of green-tinged vomiting after feeding. Examination reveals a distended, tender abdomen and reduced bowel sounds. The baby has had minimal stool output since birth. A nasogastric tube is placed, yielding bilious aspirate. Initial plain abdominal X-ray shows non-specific gas patterns without free air. What is the most likely diagnosis and the critical vascular complication if not urgently treated?

A) Pyloric stenosis; obstruction leading to gastric perforation
B) Malrotation with volvulus; midgut ischemia due to superior mesenteric artery compromise
C) Hirschsprung’s disease; toxic megacolon with mesenteric infarction
D) Duodenal atresia; high small bowel obstruction causing proximal dilation
E) Meconium ileus; inspissated stool causing distal bowel obstruction

Question 40: A newborn initially appears healthy but, on day 2 of life, develops central cyanosis, tachycardia, and visible chest pulsations over the sternum. On examination, the infant has normal lung sounds, poor oxygen saturations (~50%), and no significant respiratory distress. Chest X-ray shows pulmonary artery dilation, and echocardiography reveals right ventricular hypertrophy and right ventricular outflow tract obstruction. Which of the following is the most likely diagnosis?

A) Tetralogy of Fallot
B) Persistent pulmonary hypertension of the newborn (PPHN)
C) Pulmonary valve stenosis
D) Transposition of the great arteries (TGA)
E) Coarctation of the aorta

Question 41: A 2-year-old child is observed to rapidly acquire new cognitive and motor skills following exposure to a highly stimulating environment. Neurobiologically, this developmental window is characterised by an abundance of modifiable synapses. Which of the following best describes the dominant neural process at this stage?

A) Activity-dependent synaptic proliferation enhancing neural plasticity
B) Activity-independent pruning of excess neuronal connections
C) Programmed apoptosis regulating final neuronal numbers
D) Early onset of oligodendrocyte-mediated myelination across all brain regions
E) Genetically pre-determined stabilisation of cortical neural networks

Question 42: A 5-month-old infant is brought for a routine check-up. The baby can now lift their chest off the ground when lying prone, grasp objects and transfer them between hands, and shows recognition of their own name. However, the clinician notices persistent asymmetric tonic neck reflex (“fencing position”) when the infant’s head is turned. What is the most concerning implication of this finding?

A) Normal persistence of neonatal reflexes at this age
B) Early sign of upper motor neuron dysfunction
C) Delayed fine motor development but normal gross milestones
D) Cerebellar hypoplasia affecting coordination
E) Normal variant due to slower physical maturation

Question 43: A 2-year-old child is brought to clinic for a developmental assessment. The child is able to walk steadily but places both feet on each step while climbing stairs. She can stack blocks and scribble, uses two-word phrases such as “more juice,” but still struggles to fully undress without assistance. Which of the following best describes her development?

A) Normal for age
B) Gross motor delay
C) Fine motor delay
D) Language delay
E) Social delay

Question 44: A child presents for a routine developmental check-up and the following observations are noted:

• Gross Motor: The child confidently climbs stairs, placing one foot on each step, and can hop on one foot with some support.
• Fine Motor: The child is able to draw a simple circle and shows increased control when using drawing tools.
• Language: The child speaks in short sentences (e.g., “I want it”) and uses basic pronouns (e.g., “me,” “you”).
• Social: The child is able to name friends and demonstrates increasing independence, including being mostly out of nappies.

Which developmental stage is most consistent with these observations?

A) 2 years
B) 3 years
C) 4 years
D) 5 years
E) 6 years

Question 45: At 6-8 weeks of age, which of the following would most accurately describe the infant’s typical developmental milestones?

A) Fine motor: Reaching for and grasping objects with both hands
B) Gross motor: Lifting head while prone, but unable to support head for long
C) Social: Smiling at familiar faces but not reacting to strangers
D) Speech: Vocalising sounds, such as cooing or gurgling, but no clear responses to speech
E) Cognitive: Beginning to recognise and respond to visual stimuli, tracking objects briefly with eyes

Question 46: A 5-year-old child with developmental delay and dysmorphic features undergoes a genetic evaluation. The paediatrician suspects a chromosomal abnormality but the standard karyotype fails to reveal any abnormalities. The clinician proceeds to chromosome microarray testing (CMA). Which of the following is the most likely benefit of this test in this clinical scenario?

A) CMA can detect single nucleotide polymorphisms (SNPs), which are typically associated with developmental delays.
B) CMA can identify submicroscopic chromosomal deletions and duplications, which may not be detectable by conventional karyotyping, thus helping explain the child’s developmental delay.
C) CMA is more effective than traditional karyotyping for detecting large chromosomal aneuploidies, such as trisomy 21, in patients with developmental delays.
D) CMA is ideal for detecting epigenetic alterations like DNA methylation patterns, which may be related to certain developmental disorders.
E) CMA is particularly suited for detecting mutations in mitochondrial DNA, which are a common cause of early-onset developmental delays in children.

Question 47: A newborn presents with congenital heart defects, facial dysmorphia, and recurrent infections. Genetic testing reveals a deletion on chromosome 22, leading to a diagnosis of DiGeorge syndrome. The pathogenesis of this syndrome primarily involves developmental failure during which embryological process?

A) Disruption of neural crest cell migration leading to abnormalities in the development of the third and fourth pharyngeal pouches.
B) Abnormal differentiation of mesodermal cells, affecting the development of the cardiac outflow tract and pharyngeal arches.
C) Defective mesonephric duct development leading to abnormal kidney and ureteral formation.
D) Failure of the ectodermal layer to differentiate into neural tube structures, leading to neural defects.
E) Impaired formation of the notochord, resulting in axial skeletal abnormalities and malformations.

Question 48: A 28-year-old woman undergoes genetic testing due to a family history of breast cancer. The test identifies a single nucleotide polymorphism (SNP) in the BRCA1 gene that has not been previously reported. Genetic counsellors classify this variant as a “Variant of Uncertain Significance” (VUS). Which of the following is the most accurate explanation for why this variant is classified as a VUS?

A) The variant has been shown to increase the risk of breast cancer in familial studies but lacks sufficient evidence in the general population.

B) The variant alters a known functional domain of the BRCA1 protein, but its effect on protein function remains unclear due to inconsistent experimental findings.

C) The variant has been shown to be benign in multiple independent cohort studies and does not alter protein function.

D) The variant is located in a non-coding region and is thought to disrupt regulatory elements, but there is no functional evidence supporting its role in cancer.

E) The variant occurs in a highly conserved region of the genome but does not alter protein function, thus making it unlikely to be pathogenic.