13. Factor X Deficiency

Factor X Deficiency

  • Congenital or Acquired
  • Congenital: autosomal recessive
  • Variable bleeding tendency at any age
    - Severe (<1%): umbilical stump bleeding
    - Less severe: post-hemostatic challenge
    - Mildly affected: bruising, menorrhagia

Heterozygotes (1:500 incidence)

  • Usually asymptomatic
  • Rarely have bleeding thought to be 2° to either:
    - Insufficient enzymatic activity of wild type
    - Inhibitory or competitive effect of mutant

Homozygotes (1:1,000,000)

  • One of the rarest inherited clotting disorders
  • Patients are usually seriously affected
  • More frequent in consanguineous marriages