Factor XI Deficiency in Ashkenazi Jews in Israel

Abstract
Severe factor XI deficiency, which is relatively common among Ashkenazi Jews, is associated with injury-related bleeding of considerable severity. Three point mutations — a splice-junction abnormality (Type I), Glu117→Stop (Type II), and Phe283→Leu (Type III) — have been described in six patients with factor XI deficiency. Clinical correlations with these mutations have not been carried out. We determined the relative frequency of the mutations and their association with plasma levels of factor XI clotting activity and bleeding, analyzing the mutations with the polymerase chain reaction and restriction-enzyme digestion.