A natural variant with a point mutation resulting in a homozygous Arg to His substitution at position 388 in prothrombin

Prothrombin deficiency is probably the rarest inherited bleeding disorder with two phenotypes: (i) hypoprothrombinemia, with a concomitant decrease in prothrombin antigen and activity; (ii) dysprothrombinemia, with a decrease in prothrombin activity but normal or sub-normal antigen levels. Bleeding