Factor VII Deficiency

(Also known as Alexander's Disease, Stable Factor Deficiency, or Proconvertin Deficiency. Not to be confused with acquired Factor VII Deficiency, which is associated with liver disease.)

Factor VII deficiency was first recognized in 1951, and originally named Serum Prothrombin Version Accerlerator (SPCA) deficiency. Although the published incidence of Factor VII deficiency is estimated at 1 in 500,000, the disorder may be more common. It is inherited in an autosomal recessive fashion, which means it affects men and women equally.

The Factor VII protein is part of the cascade of clotting factors that form the chain leading to a protective blood clot. Factor VII deficiency is usually severe. In fact, patients with less than 1% Factor VII activity experience similar symptoms to hemophilia.

Symptoms

People with severe factor VII deficiency:

  • Are prone to joint bleeds
  • In addition to spontaneous nosebleeds, people can experience bleeds in the stomach, intestines and urinary tract
  • Head bleeds and muscle bleeds have also been reported
  • Women can have severe menorrhagia

Diagnosis

Diagnosis is made through an Activated Partial Thromboplastin Time (aPTT) Test, Prothrombin Time (PT) Test and Thrombin Time (TT) Test. Diagnosis can be confirmed with a Factor VII assay. There have been instances of combined Factor VII deficiencies with cases of Factors II, IX and X.

Treatment

In July 2005, Novo Nordisk received FDA-approval for a new usage indication of its recombinant Factor VII product Novoseven® to treat bleeding episodes in patients with factor VII deficiency. Prothrombin complex concentrates (PCCs) can also be used to treat Factor VII deficiency. However, the amount of factor VII contained in these products vary considerably among PCCs. Not only is there a marked difference in factor content between the different commercial preparations, but factor content can also vary between product lots produced by the same manufacturer.

Patients with factor VII deficiency can also be treated with fresh frozen plasma (FFP). However, volume constraints may limit the amount of FFP that can be used. There have been cases of thrombosis reported in people with factor VII deficiency.