Rh null blood 

     

        The surface of the blood cells is coated with up to 342 antigens whose determines the person's blood type. In 1961, a woman had this rarest blood group identified in Australia. By 2010 nearby 43 people had this blood group in worldwide.  This blood group is called as "Golden blood". 

This blood type people are Universal Donors. They can donate blood but it doesn't cross boards. It has many procedures to cross. Many countries didn't allow it. This blood type has no side effects or healthy complications.  However because of the rarity of their blood they need to be extra careful.