Paediatricsmiddle twist
A 14-year-old boy is brought by his mother because he is the shortest in his class and is being teased. His height has followed a line just below the 3rd percentile since he was 5 years old, and he has grown 5 cm in the past year; his weight is proportionate to his height. He has no abdominal symptoms and opens his bowels daily, and his sense of smell is normal. His testicular volume is 3 mL bilaterally and he has no pubic hair. A radiograph of the left wrist shows a bone age of 11 years and 6 months. His father shaved for the first time at 19 and grew during his apprenticeship. Which one of the following best explains his short stature and lack of pubertal development?