Factor XI deficiency with a novel homozygous mutation Trp599Arg near the C-terminal region

We identified a novel mutation in an asymptomatic 72-year old Japanese woman with severe factor XI (FXI) deficiency. Sequence analysis showed a homozygous missense mutation Trp599Arg (g.234T-->C according to Genbank accession number [M20218][1]). This residue belongs to a region conserved in human FXI and the FXI of several animals. Molecular modeling showed that the Trp599 residue is positioned in an alpha helix in the C-terminal region of the FXI molecule. [1]: /lookup/external-ref?link_type=GEN&access_num=M20218&atom=%2Fhaematol%2F90%2F7%2F999.atom