该基因编码凝血因子viii，参与凝血的内在途径；因子viii是因子ixa的辅因子，在ca+2和磷脂存在下，将因子x转化为激活的x a。这个基因产生两个交替剪接的转录本转录变体1编码一种大的糖蛋白，亚型a，在血浆中循环，并与非共价复合物中的血管性血友病因子相关这种蛋白质经历多重分裂事件。转录变异体2编码一种假定的小蛋白，亚型b，主要由viiic因子的磷脂结合区组成。这个结合域是凝血活性所必需的。该基因缺陷导致血友病A，一种常见的隐性X连锁凝血障碍。[由RefSeq提供，2008年7月]
This gene encodes coagulation factor VIII, which participates in the intrinsic pathway of blood coagulation; factor VIII is a cofactor for factor IXa which, in the presence of Ca+2 and phospholipids, converts factor X to the activated form Xa. This gene produces two alternatively spliced transcripts. Transcript variant 1 encodes a large glycoprotein, isoform a, which circulates in plasma and associates with von Willebrand factor in a noncovalent complex. This protein undergoes multiple cleavage events. Transcript variant 2 encodes a putative small protein, isoform b, which consists primarily of the phospholipid binding domain of factor VIIIc. This binding domain is essential for coagulant activity. Defects in this gene results in hemophilia A, a common recessive X-linked coagulation disorder. [provided by RefSeq, Jul 2008]