Acquired Hypoprothrombinemia is a disease that only effects about 1 in 2 million people.

A.H. is when the body is lacking the protein Prothrombin that synthesizes Vitamin K and causes blood clotting disorders such as bleeding gums, nosebleeds, easy bruising or excessive bleeding. There are actually two types of prothrombin deficiencies, one is congenital which means the person effected was born with it, and the other is acquired, meaning that there is some sort of underlying health problem that caused A.H. later in life. If the underlying cause can be treated, so can the A.H.

Here are a few links to find out more:
MD Guidelines
Check Orphan
Medscape