What is known: • Marfan syndrome is a hereditary connective tissue disorder. • Marfan syndrome affects multiple systems.

What is new: • Adolescents with Marfan syndrome perceive (1) problems in keeping up with peers in school, sports, leisure, friendships/relationships and work (2) to differ from peers due to their appearance and disability. • An adolescent Marfan syndrome-specific International Classification of Functioning, Disability and Health for Children and Youth model derived from the data describing the adolescent perceived impact of Marfan syndrome on functioning, disability and contextual factors.