The first cases of Fitzgerald factor deficiency in the Orient: three cases in one family.

Asymptomatic, female, 56-year-old identical Japanese twins were found to have a severe abnormality in the surface-mediated intrinsic coagulation, fibrinolysis and esterolytic activity. These defects were thought to be due to the lack of Fitzgerald factor, because of the prolongations of kaolin-activated partial thromboplastin time and kaolin-activated euglobulin lysis time that were not corrected by the addition of Fitzgerald trait-plasma but were corrected to normal levels by the addition of isolated bovine high-molecular-weight kininogen, Fletcher trait-plasma or Hageman trait-plasma.