Hereditary lymphedema is a primary lymphedema – swelling that results from abnormalities in the lymphatic system that are present from birth. Swelling may be present in a single affected limb, several limbs, genitalia, or the face. It is sometimes diagnosed prenatally by a nuchal scan or post-natally by lymphoscintigraphy. The most common form is Meige disease that usually presents at puberty. Another form of hereditary lymphedema is Milroy's disease caused by mutations in the VEGFR3 gene. Hereditary lymphedema is frequently syndromic and is associated with Turner syndrome, lymphedema–distichiasis syndrome, yellow nail syndrome, and Klippel–Trénaunay–Weber syndrome.