血友病甲是一种具有不同分子缺陷的异质性出血性疾病.在正常凝血过程中,因子Ⅷ(FⅧ)是FⅨa活化FⅩ时所需的辅因子.而FⅧ本身也需要经过凝血酶的酶解而活化.FⅧ的一个成熟单链蛋白质含有2332个氨基酸,经酶解后产生92到200KDa氨基端的重链与80KDa的羧基端轻链.凝血酶再作用于FⅧ重链中精氨酸372形成54KDa及44KDa二条肽链时产生凝血活性.作者研究了一例血浆中FⅧ活性为0.05单位/ml,FⅧ抗原活性为3.25单位/ml,临床上属中型的 Hemophilia A is a heterogeneous haemorrhagic disease with different molecular defects. During normal coagulation, Factor VIII (FVIII) is a cofactor required for FIXa to activate FX, while FVIII itself also needs to pass thrombin A mature single-stranded protein of FⅧ contains 2332 amino acids and is enzymatically hydrolyzed to give a 92 to 200 kDa amino-terminal heavy chain and a carboxy-terminal light chain of 80 kDa. Thrombin is then acted on arginine 372 in the FⅧ heavy chain The formation of 54KDa and 44KDa two peptide chains produce clotting activity of the author studied a plasma FⅧ activity of 0.05 units / ml, F Ⅷ antigen activity of 3.25 units / ml, clinically medium