The incidence of factor X deficiency is estimated at 1 in 500,000 people. It is inherited in an autosomal recessive fashion, which means it is equally likely to affect men and women.
The factor X protein activates the enzymes that help to form a blood clot. There are several genetic variations of factor X with varying degrees of severity. People with mild forms of the deficiency usually do not have bleeding episodes, but do have bleeding after trauma or surgery. Patients with severe forms of the disease commonly have joint bleeding, gastrointestinal bleeds, and hematomas. Spontaneous head bleeds, spinal cord bleeds and bleeding at the site of the umbilical cord have also been reported. Women with factor X deficiency may have menorrhagia or be susceptible to first trimester miscarriage.
Diagnosis is made through a bleeding time test, prothrombin time (PT) test and partial thromboplastin time (PTT) test. Diagnosis can be confirmed by a factor X assay, or a ruffle viper venom time assay.
Treatment
No factor X concentrates are currently available, so fresh-frozen plasma is normally used as treatment. Prothrombin complex concentrates (PCCs) have been used in some patients, but it is important to know that the amount of factor X in each product in not consistent. There has also been a reported risk of thromboembolic complications with PCC product usage.
Last Updated:
6/24/2009 6:50 PM