“…Factor XI (FXI) deficiency is a rare, inherited bleeding disorder (also known as hemophilia C, plasma thromboplastin antecedent deficiency or Rosenthal syndrome) that is typically asymptomatic and initially presents with unexpected bleeding after surgery or trauma. In the general population, the prevalence is exceedingly rare (1:1,000,000), but in the Ashkenazi Jewish population, the reported prevalence varies in the literature [1][2][3][4][5][6]. Approximately 1:8 individuals are heterozygous and 1:190 are homozygous for a mutation on the F11 gene, the most common gene mutation that results in FXI deficiency in this population [2].…”