BRBNS is a venous malformation, formerly, though incorrectly, thought to be related to the hemangioma. It carries significant potential for serious bleeding.Lesions are most commonly found on the skin and in the small intestine and distallarge bowel. It usually presents soon after birth. BRBNS used to be thought of as having no genetic inheritance however, in 1995 doctors discovered that information to be false, it has been suggested that it may represent a manifestation of familial venous malformation, and may be associated with TEK tyrosine kinase. Gareth Fisher, a medical student at a London hospital interviewed a patient with the condition in 2012, who disclosed he had a dizygotic twin brother with the same condition, supporting a genetic link. Some of this patients malformations were in the proximity of 20mm in diameter.