Down Syndrome: Clinical Case and Viva QnA

Clinical Case of Down Syndrome

A 2-day-old newborn male is referred to the pediatric clinic for evaluation of possible Down syndrome. The infant was born at 38 weeks gestation to a 38-year-old primiparous mother via spontaneous vaginal delivery. Pregnancy was uncomplicated, and prenatal screening tests were declined.

On physical examination, the infant presents with:

• Hypotonia
• Flat facial profile
• Upslanting palpebral fissures
• Small, low-set ears
• Single palmar crease on the right hand
• Increased space between first and second toes (sandal gap)
• Weak Moro reflex

Cardiac auscultation reveals a grade 3/6 systolic murmur, loudest at the left sternal border. Abdominal examination is unremarkable.

A karyotype analysis is ordered, which confirms trisomy 21 (47,XY,+21), establishing the diagnosis of Down syndrome.

Varieties of Presentation of Down Syndrome

1. Classical Trisomy 21:

   • Most common form (95% of cases)
   • Characteristic facial features (flat face, upslanting palpebral fissures, small nose)
   • Hypotonia
   • Intellectual disability
   • Congenital heart defects (e.g., atrioventricular septal defect)

2. Mosaic Down Syndrome:

   • Milder phenotypic features
   • Variable degree of intellectual disability
   • May have fewer health complications
   • Some cells have trisomy 21, while others have normal karyotype

3. Translocation Down Syndrome:

   • Occurs in about 4% of cases
   • Extra chromosome 21 material attached to another chromosome (usually 14)
   • Can be inherited from a parent with balanced translocation
   • Similar physical features to classical trisomy 21

4. Brushfield Spots Variant:

   • Prominent white or grayish spots on the iris
   • More noticeable in individuals with lighter-colored eyes
   • Present in about 85% of individuals with Down syndrome

5. Duodenal Atresia Presentation:

   • Presents with bilious vomiting in the neonatal period
   • Abdominal distension and failure to pass meconium
   • Occurs in approximately 5-7% of infants with Down syndrome
   • Requires surgical intervention

VSD Quiz for Medical Students & Professionals

This interactive quiz component covers essential concepts about Ventricular Septal Defects (VSD) in pediatric cardiology. It includes 25 high-yield viva questions with detailed answers

Question 1 of 30

Image Gallery

These medical images are collected from various internet sources for educational purposes. Each image includes a source link; by clicking the source, you will be taken to the corresponding source website page.

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Unilateral morning glory optic disc anomaly in a case with Down syndrome.

Fundus photographs of the right eye (A) and the left eye (B).(source)

Riga-Fede disease in a child with Down syndrome.

Persistent lingual ulceration (Riga-Fede disease) in an infant with Down syndrome and natal teeth.(source)

A newborn with cardiomegaly.

An infant with Down's syndrome was noted to have hypoxemia and tachypnea at birth.(source)

Chimeric Fetus

Autopsy and karyotypes of the chimera fetus. The aborted fetus exhibits normal external genitalia (A) and no characteristics typical of Down syndrome except the enlarged gap between the first and the second toes (B) was observed. The fetal karyotypic ratio of 46,XY (C) to 47,XX,+21 (D) in cortical cells was 11:9.(source)

Disclaimer

The notes provided on Pediatime are generated from online resources and AI sources and have been carefully checked for accuracy. However, these notes are not intended to replace standard textbooks. They are designed to serve as a quick review and revision tool for medical students and professionals, and to aid in theory exam preparation. For comprehensive learning, please refer to recommended textbooks and guidelines.