How would you manage a patient with family history of protein S deficiency, now with provoked VTE and low protein S?   

Low protein S would need to be checked at the appropriate time. It should not be checked during acute thrombosis It should not be checked while the patient is on DOAC If the provoking factor was estrogen containing contraceptives, testing should not be performed until the patient has been off of ...

I agree with Dr. @Archibald, and I would add that the "family history" can also be derived from situations where family members had thrombosis and were tested at the wrong time. For example: the mother of the patient was tested during the acute thrombotic setting and/or during coumadin therapy when ...