Many times if you need to search a subject you need to punch in research (your subject) research.
Marfan syndrome. ..Haven't heard that in awhile, it is sometimes associated with genetic disorders like homocyctenaria. It's becoming more prevelent in societies with compromised heart/blood vessels. It just means a large (over genetic forebearance), person. This can be concerning due to taxation of heart and vessels that tend to build up platlets along vessel walls.
Have you talked to your friend about this? They'll most likely be willing to share and kind of complimented that someone shows enough interest to ask.
Hope this has been helpful.
Klem