Lymphedema is a swelling that is caused by the abnormal accumulation of lymph fluid in tissue, resulting from faulty development of the lymphatic system or blockage of the lymph vessels. It usually causes swelling of the extremities.
These vessels are small channels like blood vessels that contain a clear fluid called lymph. When lymphedema presents at birth or appears in childhood, it is referred to as primary lymphedema.
When its cause is attributed to trauma, infection, or surgical removal of lymph nodes, it is referred to as secondary lymphedema.
The two types of primary lymphedema are idiopathic (unknown cause) and hereditary. Hereditary lymphedema is caused by either an autosomal dominant or recessive inheritance. It can be associated with syndromes (other anomalies) as well. The most common form of primary congenital lymphedema is lymphedema praecox, or Milroy’s Disease. It is a hereditary from of lymphedema with autosomal dominant inheritance.
We are closer to establishing the genetic basis for these disorders. Some mutations in the vascular endothelial growth factor receptor (VEGFR3) have been found and others are being investigated.
All patients with lymphedema should be evaluated by a genetic counselor.