Paediatricsmiddle twist
A 3-week-old boy has just had a pyloromyotomy for infantile hypertrophic pyloric stenosis. He is his parents' first child and neither parent nor any grandparent was affected. At the follow-up visit his parents ask what the risk is for children born later into the family, including to his aunts and uncles. Which one of the following children carries the highest risk of developing the same condition?