How do changes to genes cause primary lymphoedema?
Primary lymphoedema is a condition in which the lymphatic system does not work properly. There is usually a structural or functional abnormality within the lymphatic system. This leads to a abnormal build-up of fluid in the body’s tissues.
A picture of a patient with primary lymphoedema and very swollen toes and dorsum (top) of the foot is shown below.
Primary lymphoedema can be caused by problems with the genes that regulate the development and function of the lymphatic system. Mutations in certain genes, such as VEGFR3, FOXC2, and SOX18, have been identified as causing primary lymphoedema.
These genetic mutations can lead to abnormal development of the lymphatic vessels, resulting in a reduced ability to transport lymphatic fluid and an increased risk of swelling.
In some cases, primary lymphoedema is inherited in an autosomal dominant pattern, meaning that an affected person has a 50% chance of passing the condition on to each of their children, however, there is usually variability in symptoms and severity even within the same family.