Factor V Leiden mutation is the most common inherited predisposition to excessive clotting in the United States and it is most common in the Caucasian population. Between 3 and 8% of U.S. Caucasians carry one copy of the factor V Leiden mutation and about 1 in 5,000 people have two copies of the mutation.
https://labtestsonline.org/tests/factor-v-leiden-mutation-and-pt-20210-mutation