I'm responding as a mom who has experienced all the symptoms of liver disease. I know how frightening the prognosis is. And how the difficult the symptoms can be. My advice is to work closely with your doctor. And help your son to continue doing healthy eating and activities. He will know when he has to stop. As scary as it might be, and if the doctor approves, then by all means, he should continue his studies. The mental challenge and the social network of friends will be valuable to him.
I had PSC (according to articles I looked up - mostly in males.) Don't let the "profile" thing upset you. It never bothered my doctors; they deal with the patient, not statistics. Another difficult thing is having a disease that no one is familiar with, and they look at you like you are crazy or making it up.
I hope that your son is doing okay.