Comparison of the risk of pulmonary embolism and deep vein thrombosis in the presence of factor V Leiden or prothrombin G20210A.

Iranians of whom 52 were females and 109 were males. The median age was 35, the youngest being 18 and the oldest 66 years of age. They represented individuals from all the Iranian regions who live in Tehran, the capital. For the factor V Leiden mutation 9 heterozygotes were found (frequency of 5.5%), with an allele frequency of 2.7% and for the G20210A mutation 5 heterozygotes were found (frequency of 3.1%), with an allele frequency of 1.5%. The frequency of factor V Leiden in Iran lies between those of Turkey in the west border of the country (9.8-10.3%) (11, 12) and those of Pakistan and India in the east (0-4.3%) (1, 3). Azarbaijan in the northwestern border of Iran has an heterozygous frequency as high as 14% (13) while Saudi Arabia, being southeast to Iran though not a neighbor, has an heterozygous frequency of 2.5% (4). In Iran, the prothrombin mutation has a frequency of 3.1%, comparable to that of Southern Europe (3%) (7). Since no similar data for this mutation are available for neighboring countries like Turkey, Azarbaijan, Pakistan and Saudi Arabia, it is very difficult to establish whether or not there is a west-to-east decreasing frequency of the mutation as seen for factor V Leiden. A relatively high frequency of the factor V Leiden mutation in Iranians and a frequency of the prothrombin mutation similar to that found in Europe strengthen the notion of European migration to the East toward Iran thousands of years ago.