A 25 year old male is due to be discharged from hospital following a non-traumatic Pneumothorax. He has no relevant past medical history and is usually fit and well. On the ward round it is noted that he is markedly tall and slim, and suggested perhaps that he has genetic condition predisposing him to having a pneumothorax. A referral to the genetics team is made.
Which one of the below findings would you most likely expect to see on examination based on his likely condition?