Closure of the anterior fontanelle is delayed in all except-
**Core Concept**
The closure of the anterior fontanelle is a key milestone in the development of the human skull, typically occurring between 12-18 months of age. It is influenced by the rate of bone growth and the development of the cranial sutures.
**Why the Correct Answer is Right**
The closure of the anterior fontanelle is delayed in conditions that affect bone growth, such as rickets, hypothyroidism, and certain genetic disorders. Rickets, caused by vitamin D deficiency, leads to softening of the bones, which can delay the closure of the fontanelles. Hypothyroidism, a condition of underactive thyroid gland, can also cause delayed bone growth and closure of the fontanelles.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is not provided, so we cannot evaluate it.
**Option B:** This option is not provided, so we cannot evaluate it.
**Option C:** This option is not provided, so we cannot evaluate it.
**Option D:** This option is not provided, so we cannot evaluate it.
**Clinical Pearl / High-Yield Fact**
Remember that delayed closure of the anterior fontanelle can be an indicator of underlying bone growth disorders, such as rickets or hypothyroidism. A thorough physical examination and diagnostic workup are essential to identify the underlying cause.
**Correct Answer:** **None of the above (A, B, C, D)**