Factor X Deficiency
(Also known as Stuart-Prower Factor Deficiency.)
Factor X deficiency was first discovered in a man with the surname Stuart from North Carolina. While his doctors had originally thought he might have factor VII deficiency, a woman with the surname Prower was also noted to have the same clotting abnormality. Researchers realized that this was a new factor and called it the Stuart-Prower factor. It was later renamed Factor X deficiency.
The incidence of Factor X deficiency is estimated at 1 in 500,000 births. Factor X deficiency is inherited in an autosomal recessive fashion, which means it affects men and women equally.
The factor X protein activates the enzymes that help to form a clot. Several genetic variations of Factor X with varying degrees of severity have been described in the medical literature.