Factor XI deficiencies are rare. Initially, they were described only in Ashkenazy Jews with two types of characteristic gene mutation. Now, 152 mutations have been identified, mostly in non-Jewish population.
We report the case of a deficiency identified in Arabic young girl living in West Algeria; gene sequences showed a type II mutation, frequent in Ashkenazy Jews. May be it is coincidence; but it is possible that this finding is related to the migratory story of this region.