Question

Features of hypothyroidism in infancy include the following except:

• A. Premature closure of posterior fontanelle
• B. Coarse facies
• C. Umbilical hernia
• D. Constipation

Hint:

Hypothyroidism delays bone maturation, so fontanelles do the opposite of closing early.

Answer 1

The Correct Option is A

Step 1: Congenital hypothyroidism slows growth and metabolism in the infant. Bone maturation is delayed, so the fontanelles, including the posterior fontanelle, close later than normal, not earlier.

Step 2: Classic features of the hypothyroid infant include coarse facies, a large protruding tongue, an umbilical hernia, constipation, a hoarse cry, hypotonia and prolonged jaundice. These all fit a sluggish metabolic state.

Step 3: Therefore premature closure of the posterior fontanelle is the exception, since hypothyroidism causes delayed closure. The other three options are genuine features.