Lower protein S

[Rabiul]

I have done protein S test for cerebral sinus thrombosis,and it is in the lower side,where protein C and antithrombotic factor in nomal,i hve no hereditary problem because my parents dont have any thrombotic problem...what is the reason for lower protein S,it s improtant to sah that i am taking warfarin,and i also maitain vitamin K ,is that the reason of lower protein S?