What are the specific factors that contribute most?

哪些具体因素影响最大？

But based on the currently available evidence, the EMA was not able to identify specific risk factors.

根据目前的证据，欧洲药品管理局无法确定具体的风险因素。

To confirm hemophilia A or B, tests to look at specific factor activities, and mutation testing of the genes encoding them, can be done.

为确诊血友病A或B，可以检测特定因子的凝血活性或进行基因诊断。