[Hereditary diseases with lens dislocation: clinical aspects].

Ectopia lentis is a common denominator of some connective tissue diseases such as Weill-Marchesani, Ehlers-Danlos, and Marfan's syndromes, osteogenesis imperfecta and homocystinuria. Early differential diagnosis (e.g., Marfan's syndrome vs. homocystinuria) is mandatory for prognostic (aortic aneurysm in Marfan's syndrome), therapeutic (dietetic and vitamin therapy in homocystinuria), and genetic reasons (genetic counseling).