Contributor: Gordon K. Klintworth
Lymphedema has many causes. It may be a consequence of a failure of  drainage by the lymphatic system because of an intrinsic abnormality of lymph drainage (primary lymphedema). The lymph containing pathways are believed to be congenitally defective and the lymphedema may be present at birth (Milroy disease). More often (80% of cases) the lymphedema does not become manifest until at or after puberty (Meige disease) and the edema is believed to result from a gradual obliteration of the peripheral lymphatic vessels. Primary lymphedema is often familial (30% of cases). A special rare form of lymphedema is lymphedema-districhiasis. This autosomal dominant disorder characterized by congenital districhiasis and the appearance of  lymphedema at or after puberty. Lymphedema occurs with ptosis in Noonan syndrome and Falls-Kertesz syndrome. Lymphedema may also be associated with districhiasis.