why is hemophilia b known as the christmas disease

Hemophilia B is a rare genetic condition that causes a deficiency in factor IX, a protein that helps blood clot. It is often referred to as the "Christmas disease" because it was first identified by two Scottish physicians, John Christmas and Paul Owren, in the 1950s. The name is not meant to be taken literally, but rather refers to the fact that it was discovered during the Christmas season.