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WorksheetsCase and Beyond
Total questions: 16
Worksheet time: 4mins
Case 1
A 2-year-old boy
Chief Complaints: Developmental delay, recurrent upper respiratory tract infections
Family History:
Maternal age: 39, paternal age: 41
No consanguinity
Pregnancy History:
Antenatal: Prenatal ultrasound revealed an atrioventricular (AV) canal defect
Natal: Term birth, birth weight 2600 g
Postnatal: Unremarkable
Developmental History:
Achieved head control at 9 months
Has not started walking at 18 months
Delayed speech
Physical Examination:
Head circumference: 45 cm (microcephaly)
Hypotonia
Dysmorphic facial features: upslanting palpebral fissures, epicanthus, flat nasal bridge, small mouth
Single transverse palmar crease (simian crease)
Dx?
Edward
Patau
Down
Turner
Klinefelter
Which genetic test should be performed first to confirm the suspected diagnosis in this patient?
Whole exome sequencing
Karyotype (G-banding)
MLPA
SNP Array
Hemogram
What is the most common underlying genetic mechanism responsible for this condition?
Autosomal dominant inheritance
Autosomal recessive inheritance
De novo nondisjunction during maternal meiosis
De novo nondisjunction during paternal meiosis
Balanced Robertsonian translocation inherited from a parent
If both parents have a normal karyotype, what is the approximate recurrence risk for having another child with the same condition?
Less than 1 percent
1–2 percent
25 percent
50 percent
33,3 percent
Scenario 2
A 16-year-old girl
Chief Complaints: Chest pain, palpitations, concern about tall stature
Family History:
Father 195 cm, died suddenly of cardiac cause at age 40
Mother healthy, no consanguinity
Prenatal/Birth History:
No problems during pregnancy or delivery
Birth weight 3200 g
Developmental History:
Normal development, good academic performance
Physical Examination:
Height: 187 cm, Arm span: 196 cm
Pectus excavatum
Positive wrist and thumb signs
−7 myopia (ophthalmology report)
Mild scoliosis
Dx?
Marfan syndrome
Homocystinuria
Ehler Danlos Syndrome
Loeys Dietz Syndrome
Cutis Laxa Syndrome
Which of the following is the best initial genetic test to confirm the suspected diagnosis in this patient?
Serum homocysteine level
Chromosomal microarray
FBN1 gene sequencing
Whole genome sequencing
ELN gene sequencing
What is the most urgent investigation that should be performed in this patient?
Pulmonary function test
Brain MRI
Hand X-ray for bone age
Echocardiography to assess aortic root diameter
Ophthalmologic evaluation for lens dislocation
What is the typical inheritance pattern of the condition suspected in this patient?
Autosomal recessive
X-linked recessive
X-linked dominant
Autosomal dominant
Multifactorial
Scenario 3
A 7-year-old boy
Chief Complaints: Learning difficulties, attention deficit, frequent anxious/startled behaviors
Family History:
Parents healthy, no consanguinity
Polyhydramnios during pregnancy
Prenatal/Birth History:
Term birth, birth weight: 2500 g
Hospitalized in the neonatal period due to hypercalcemia
Developmental History:
Started walking at 2 years
Speech delay, but enjoys singing
Strong social interaction skills
Physical Examination:
Broad forehead, full cheeks, short nose, wide mouth
Dental anomalies
Heart murmur
Slender body habitus, hypermobile joints
Dx?
DiGeorge syndrome
Williams syndromeı
Angelman syndrome
Kabuki syndrome
Noonan syndrome
Which genetic test is most appropriate to confirm the suspected diagnosis in this patient?
Karyotype (G-banding)
FISH targeting 7q11.23
Chromosomal microarray (CMA)
Whole exome sequencing
MLPA for RASopathy genes
Which of the following clinical findings is most characteristic of the suspected diagnosis in this patient?
A) Hypertelorism and low-set ears
Bitemporal narrowing and downslanting palpebral fissures
Supravalvular aortic stenosis with “elfin facies”
Severe hypotonia and feeding difficulties in infancy
Macroglossia and umbilical hernia
What is the typical genetic mechanism underlying this patient’s condition?
Autosomal dominant inheritance from an affected parent
Autosomal recessive inheritance
X-linked dominant inheritance
De novo microdeletion at 7q11.23
Uniparental disomy of chromosome 7
Scenario 4
An 8-month-old girl
Chief Complaints: Poor head control, feeding difficulty, respiratory distress
Family History:
Pedigree to be drawn
Maternal age: 27, paternal age: 30
Parents are first-degree cousins
History of a male sibling who died at 2 months with similar findings
Prenatal/Birth History:
Normal pregnancy, delivered at term
Birth weight: 3100 g
No perinatal complications
Developmental History:
No head control at 2 months, has never been able to sit
Tires easily during feeding, frequent aspiration episodes
Physical Examination:
Hypotonic appearance (“floppy infant”)
Reduced muscle mass
Deep tendon reflexes absent
Fasciculations on the tongue
Motor development severely delayed, mental development normal
Dx?
Congenital myotonic dystrophy
Spinal muscular atrophy (SMA) Type 1
Pompe disease
Congenital myasthenic syndrome
Charcot–Marie–Tooth disease
Which test is the best initial investigation to confirm the suspected diagnosis in this patient?
Serum laktat level
Muscle biopsy
EMG
Whole exome sequencing
SMN1 gene deletion analysis (MLPA)
What is the primary clinical reason for determining SMN2 copy number in patients with genetically confirmed spinal muscular atrophy (SMA)?
Carrier detection
Prenatal diagnosis
Predicting phenotype severity and therapeutic response
Screening eligibility
Identifying SMN1 point mutations
Which plant species did Gregor Mendel use in his experiments, thereby making foundational contributions to the science of genetics?
Dragon fruit
Avocado
Pea plant
Mango
Melon (Kelek)
