This is a rare genetic disorder characterize by the swelling of the limbs from fluid accumulation and extra eyelashes (distichiasis). It can also present additional problems such as varicose, heart abnormalities and cleft palate. The swelling of the legs usually can occur in late childhood or puberty. The exact prevalence of this syndrome is not known as the extra eyelashes can be overlooked and several of the cases often are diagnosed as having lymphedema only.
Causes
This syndrome develops as the result of a mutation in the gene FOXC2 which is responsible for the production of a protein important in the development of organs and tissues. This gene is known as transcription factor meaning it binds to certain regions of DNA to control other genes. The FOXC2 gene is important for the normal developmental process of the veins, lungs, kidneys, urinary tract, lymphatic vessels and the eyes. This syndrome is inherited in an autosomal dominant pattern meaning only one of the two copies of the gene has the mutation. The mutation can either be inherited from the parents or can develop as the result of new mutation.
Symptoms
The symptoms of this syndrome vary among the affected case. Some of the common signs and symptoms include the presence of an extra row of eyelashes and the swelling of the legs from the accumulation of lymph in the layers under the skin. The lymphedema usually affects both the legs that can cause tingling sensations, discomfort and tightness. Individuals with lymphedema can also develop cellulitis, a bacterial infection that causes swollen and reddened skin. The distichiasis can either develop as a full set of extra eyelashes or just a few extra lashes. Additional eye abnormalities can include sensitivity to light, inflammation of the inside of the eyelids (conjunctivitis) and drooping or sagging of the eyelids (ptosis). Several of the affected individuals can also develop varicose veins. Some individuals have presented congenital heart disease and irregular heartbeats (arrhythmias).
Diagnosis
The diagnosis is possible with the history of the patient and with the identification of features associated with this syndrome. Various tests may be done to understand the extent of the syndrome which can include lymphoscintigraphy or an echocardiogram. The lymphoscintigraphy uses a substance called a contrast medium which is injected into the lymphatic vessel while series of x-rays are taken. This can help determine the health and the structure of the lymphatic vessels. The echocardiogram produces images of the heart that can detect heart defects associated with this disorder. The genetic molecular testing can also help confirm the diagnosis.
Treatment
The treatment is based on the symptoms that are evident in each case. The complete decongestive therapy uses special massage along with bandaging, exercise, skin care and well-fitted compression garments. In the case of an infection, antibiotics may be required. The treatment for the extra eyelashes includes cryotherapy, lid splitting, plucking (epilation) and electrolysis. Surgery may be required depending on the additional abnormalities such as cleft palate. The genetic counseling may be beneficial for the affected individuals and their families.
References
https://rarediseases.org/rare-diseases/lymphedema-distichiasis-syndrome/
https://ghr.nlm.nih.gov/condition/lymphedema-distichiasis-syndrome#statistics
http://disorders.eyes.arizona.edu/disorders/lymphedema-distichiasis-syndrome
