Pedigree of a Yemenite Jewish family depicting a proband with severe FXI deficiency (less than 1 U/dL) caused by homozygous type II mutation and six family members who are heterozygotes. It can be seen that the 1-2-2-2 haplotype segregates with the type II mutation as in Iraqi and Ashkenazi Jewish and Arab chromosomes bearing this mutation (Fig 2).