Background: Cerebral venous sinus thrombosis (CVST) is a rare thrombotic disease with its estimated annual incidence of 3–4 cases per million. Patients with genetic thrombophilia such as prothrombin G20210A mutation display a higher propensity to CVST when compared to other venous thrombosis. The aim of the study was to assess the significance of prothrombin G20210A mutation as a risk factor for patients with CVST.

Methods: This case control study was carried out on 56 participants. They were divided into two equally groups; case group [diagnosed with CVST], control group [healthy participants]. Participants were subjected to the following: genetic and acquired risk factors for thrombosis including prothrombin gene (G20210 A) mutation, whereas patients' group were subjected to history of previous thrombosis, duration of illness, presenting symptoms, oral contraceptives or HRT usage, vasculitis, hematological disorders, presence of papilledema and cranial nerve palsy, Glasgo Coma Scale (GCS), Modified Rankin Score (mRs) at discharge.

Results: In the current study, 14.29 % of CVST patients were heterozygous for the prothrombin G20210A mutation while only one person (3.57%) in the control group showed this mutation. CoCS/HRT and protein S deficiency were significantly higher in cases than controls .Regarding radiological findings of positive and negative groups there were insignificant difference between them.

Conclusions: Our study revealed that , although the prevalence rate of PTH gene mutation in our CVST patients was higher than reported in previous studies it is still statistically insignificant risk factor for CVST.