Factor V Leiden and Prothrombin G20210A Gene Mutations Should Not Be Routinely Screened among Venous Thromboembolism (VTE) Patients in Singapore - This and Patterns of Other Thrombophilic Conditions among Our VTE Patients.

Introduction: Emerging good quality evidence has suggested that the prevalence of VTE among Asians is significant and was largely underestimated previously.

Objective and methods: We conducted a study of thrombophilic markers among our population of VTE patients to determine their prevalence and help determine the best screening strategy among our increasing number of VTE patients. Three major hospitals in the country were involved in this study.

Results: Of 254 patients recruited, ethnic distribution was as follows: Chinese 68.1%, Malays 17.3%, Indians 12.6%, Others 2%. The ratio of males to females was 2:3. Major risk factors such as surgery, trauma and malignancy was recordedand identified in about 80% of the population. Twenty-one percent of patients had pulmonary embolism. Positive results of thrombophilic markers were as follows: protein C deficiency, 4 patients (1.52%); protein S deficency, 26 (10.24%), antithrombin III deficiency, 11 (4.33%); lupus anticoagulant, 9 (3.54%); anticardiolipin antibody IgG, 3 (1.18%); anticardiolipin antibody IgM, 6 (2.36%); hyperhomocysteinemia, 32 (12.6%); factor V Leiden gene mutation, 0 (0%); prothrombin 20210 gene mutation, 0 (0%). The prevalence of at least one thrombophilic condition was found in about one third of our patients. The relative risks of these thrombophilic conditions will be compared with a healthy control population.

Conclusion: Among our VTE patients, the most commonly associated thrombophilic conditions were protein S and antithrombin III deficiencies. The factor V Leiden and prothrombin G20210A mutation did not feature at all in our patient population and is consistent with other studies on Asian populations. These tests should not be included as part of our thrombophilic screening.