Lymphedema-distichiasis syndrome: a distinct type of primary lymphedema caused by mutations in the FOXC2 gene

Lymphedema-distichiasis syndrome (LD, OMIM 153400) is an autosomal dominant disorder with variable expression. It is caused by mutations in the FOXC2-gene, which codes for a forkhead transcription factor involved in the development of the lymphatic and vascular system. LD is characterized by late childhood or pubertal onset lymphedema of the limbs and distichiasis (double row of eyelashes). While the latter is the most common expression of LD, venous insufficiency occurs in half of the patients. Other associations have been reported, including congenital heart disease, ptosis, cleft lip/palate and spinal extradural cysts. Here we describe a family with classical lymphedema-distichiasis syndrome caused by a duplication in the FOXC2-gene.