RGD uses the Human Disease Ontology (DO, https://disease-ontology.org/) for disease curation across species. RGD automatically downloads each new release of the ontology on a monthly basis. Some additional terms which are required for RGD's curation purposes but are not currently covered in the official version of DO have been added. As corresponding terms are added to DO, these custom terms are retired and the DO terms substituted in existing annotations and subsequently used for curation.
This is a very rare condition characterized by extensive, circumscribed venous malformations (phlebectasias) involving all veins, including the smallest ones, on the arms and legs. It is present at birth (congenital) and is progressive during life. The venous dilatation can be seen beneath the skin on the arms and legs. It may occur on one or both sides.