An 18-month-old boy has recurrent morning hypoglycaemic seizures, a micropenis, and height on the 3rd centile with weight proportionate. Bone age is delayed by 2 years. IGF-1 and IGFBP-3 are both low, and peak growth hormone on two provocation tests is 4 ng/mL. What is the most likely diagnosis?
- A Idiopathic short stature
- B Primary hypothyroidism
- C Growth hormone deficiency ✓
- D Malnutrition
Correct answer: C. Growth hormone deficiency
Explanation
Micropenis and fasting hypoglycaemia in a male infant are classic neonatal clues to growth hormone deficiency, since GH supports penile growth and counter-regulates glucose. Proportionate short stature, delayed bone age, low IGF-1 and IGFBP-3, and a subnormal peak GH response (below 10 ng/mL by Indian exam convention) on two separate stimulation tests confirm the diagnosis. Malnutrition lowers IGF-1 but raises GH levels, and hypothyroidism does not cause micropenis or hypoglycaemia.
Reference: Nelson Textbook of Pediatrics, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.