GJC2-related late-onset primary lymphedema is a rare genetic condition that mainly affects the lymphatic system. People with this condition develop lymphedema, which is swelling caused by a buildup of lymph fluid in all four limbs. The age at which the swelling appears can vary greatly, from birth to adulthood. In some cases, swelling in the upper limbs may not appear until later in the disease course. The severity of symptoms can vary, with some people experiencing milder forms while others may have more pronounced swelling and complications. In severe cases, there can be recurring episodes of cellulitis and skin infections. Varicose veins and problems with the veins have also been reported, showing that the condition can affect both the lymphatic and venous systems.

Common symptoms include swelling (lymphedema) in all four limbs. In early stages, the lower limbs are usually affected and later the upper limbs may be involved. Severe cases might include recurrent episodes of cellulitis and skin infections. Some people might also experience varicose veins and signs of venous incompetence.

This condition is described as a genetic form of primary lymphedema, which means it is linked to inherited factors. Although the specific genetic details are not fully detailed here, the name suggests that changes related to the GJC2 gene are involved. More detailed information on the exact genetic mechanisms is limited at this time.