The prevalence of inherited thrombophilias in a Caucasian Australian population

Aims: To describe the prevalence of four inherited thrombophilias and their combinations for the first time in a large Caucasian Australian population. Methods: Newborn screening cards of 883 Caucasian babies born in South Australia in 1986-1999 were de-identified and tested for the following inherited thrombophilic polymorphisms: factor V Leiden (G1691A), prothrombin gene mutation (G20210A), methylenetetrahydrofolate reductase gene ( MTHFR) C677T and A1298C, as well as compound heterozygosity for the MTHFR polymorphisms. Results: The birth prevalences of heterozygosity and homozygosity for the four thrombophilic polymorphisms were: factor V Leiden 9.5% and 0.7%, prothrombin gene 4.1% and 0.2%, MTHFR C677T 37.3% and 12.4%, and MTHFR A1298C 38.3% and 11.8%, respectively. Compound heterozygosity for MTHFR C677T and A1298C was seen in 16.6% of the population. Overall, 64.2% and 24.5% of the population studied were homozygous and heterozygous, respectively, for at least one of the four polymorphisms studied. Conclusion: Inherited thrombophilic polymorphisms are common in the Caucasian Australian population. Knowledge of the background prevalence of these polymorphisms will allow further study of their associations in future disease research.