Paediatricsmiddle twist
A 14-year-old boy is brought by his parents because he is the shortest in his class and has no signs of puberty. His height is on the 3rd centile and he has grown 5 cm in the past year; his weight is on the 5th centile. Testicular volume is 2 mL bilaterally and there is no pubic hair. He can smell coffee and peppermint, his arm span equals his height and there is no goitre. A wrist radiograph reports a bone age of 12 years. His father first shaved at 17. Which one of the following is the most likely underlying cause?