Incidental Finding of Combined Factor V and VIII Deficiency in the Setting of a Preoperative Evaluation: A Case Report.

We present a case of a patient who was found to have incidental deficiencies of combined factor V (F5) and factor VIII (F8) identified on pre-operative screening. Our patient is a 61-year-old male with a past medical history of hyperparathyroidism, hypercalcemia, and mild kidney dysfunction. He was referred to the hematology clinic as he was found to have an abnormal activated partial thromboplastin time (aPTT) while being evaluated preoperatively for a parathyroidectomy. The patient did not have any significant history of bleeding, bruising, or hemarthrosis but recalls occasional nosebleeds in childhood. The patient was screened with PT/aPTT by his primary care prior to surgery. This revealed a mildly prolonged aPTT and a normal prothrombin time (PT), and the patient was referred to hematology. Further studies one week later revealed decreased F5 and F8 activity. von Willebrand Factor antigen levels were normal. CBC, protein C and S activity, and antiphospholipid antibody screening were normal as well. This is postulated to arise from a monogenic mechanism, classically through biallelic variants in LMAN1 or MCFD2, leading to combined F5 and F8 deficiency. Rarely, it can be of digenic inheritance with separate defects in F5 and F8. We outline considerations for perioperative evaluation and family counseling in the setting of a rare coagulopathy.