Morning Quiz ☕️ 

A 2-month-old boy is brought to the emergency department due to:

• Progressively worsening "floppiness"

• Poor feeding

• Decreased stool frequency (every other day, small and pellet-like)

Birth & Developmental History

• Born in Eastern Europe via uncomplicated vaginal delivery to a 38-year-old woman.

• Recently immigrated to the United States.

• Parents describe him as a "good baby" who:

  • Rarely cries

  • Sleeps through the night

  • Recently difficult to rouse for breastfeeding

Physical Examination Findings

• Hypotonia

• Large anterior fontanelle

• Large tongue

• Reducible umbilical hernia

• Unable to hold head erect

• No other abnormalities noted

Question

Which of the following is the most likely cause of this patient's condition?

Options

A. Botulism
B. Down syndrome
C. Galactosemia
D. Hirschsprung disease
E. Hypothyroidism 
F. Phenylketonuria

Correct Answer 🎯: E. Hypothyroidism 

⚙️

🧠 Congenital Hypothyroidism

(most likely cause due to endemic iodine deficiency in Eastern Europe)

⬇

↓ Thyroid Hormone (T3, T4) production during fetal/neonatal period

⬇

↓ Cellular Metabolism across multiple tissues

⬇

↓ Energy Production + Protein Synthesis

⬇

Impaired Brain Development 🧠

→ Lethargy (“good baby” who rarely cries, sleeps excessively)

→ Poor feeding (difficult to rouse for breastfeeding)

→ Hypotonia (unable to hold head erect)

⬇

↓ Gastrointestinal Motility

⬇

Constipation (small, pellet-like stools every other day)

⬇

↓ Muscle Tone + Myxedema Effects

⬇

Large Tongue (macroglossia)

• Hypotonia (floppy infant)

• Umbilical Hernia (weak abdominal muscles)

⬇

↓ Bone Development

⬇

Large Anterior Fontanelle (delayed fontanelle closure)

Differential Table ⚖️

Visual Cheat Chart 📈 

Practice Questions ⏳️ 

Most Importantly Solve UWorld Questions with IDs:

1407, 19752, 19753, 20168, 19747, 19756

Stay Hungry, Stay Curious!

Your Brother in This Struggle

Dr. Shoaib Ahmad