A child is below the third percentile for height. His growth velocity is normal, but chronologic age is more than skeletal age. The most likely diagnosis is –
**Core Concept**
The child's condition suggests a delay in bone maturation, which is a hallmark of constitutional delay of growth and development (CDGD). CDGD is characterized by a normal growth velocity but a discrepancy between chronologic and skeletal ages, often with a family history of similar growth patterns.
**Why the Correct Answer is Right**
In CDGD, growth hormone secretion is normal, and growth velocity is maintained, but the onset and progression of puberty are delayed. This results in a discrepancy between chronologic and skeletal ages. The child's height is below the third percentile, indicating a growth delay, but the normal growth velocity suggests that the growth plates are still active.
**Why Each Wrong Option is Incorrect**
**Option A:**
This option might be considered if the child had a history of trauma, infection, or other systemic illness affecting growth. However, the child's normal growth velocity and lack of other symptoms make this a less likely diagnosis.
**Option B:**
This option could be considered if the child had a history of nutritional deficiencies or other systemic conditions affecting growth. However, the child's normal growth velocity and lack of other symptoms make this a less likely diagnosis.
**Option C:**
This option might be considered if the child had a history of genetic disorders or chromosomal abnormalities affecting growth. However, the child's normal growth velocity and lack of other symptoms make this a less likely diagnosis.
**Clinical Pearl / High-Yield Fact**
Constitutional delay of growth and development is a common condition, and children with CDGD often have a family history of similar growth patterns. It is essential to differentiate CDGD from other growth disorders, such as growth hormone deficiency or Turner syndrome.
**Correct Answer: C. Growth Hormone Deficiency**