Stuart Prower deficiency

Deficiencies of Factor's II, V and X are inherited as autosomal recessives. They occur rarely with reported incidences between 1 in 500 000 to 1 in 1 000 000, and result from the production of altered inactive forms of the relevant protein.

Laboratory tests show increased prothrombin and partial thromboplastic times - not corrected by administration of vitamin K; other tests are normal.

Diagnosis is by specific factor assay.

Acquired deficiencies of these diseases may result from:

• antibodies to the appropriate Factor
• lupus anticoagulants - e.g. systemic lupus erythematosus
• systemic amyloidosis - amyloid fibrils bind to Factor X

Notes:

• descriptive name for factor II is prothrombin
• descriptive name for factor V is labile factor
• descriptive name for factor X is Stuart-Power factor