F XI Deficiency Mutation Database©
2015 Update!!

The FXI deficiency database (version 2.2) is being migrated to a new format with the same URL and we hope this upgraded website will be ready in 2016. On the changeover, this old website will be renamed www.factorxi2009.org.

2009 Updates!! Database Version 2.2

The FXI deficiency database has recently been updated (September 2009) to include several new mutations and publications

Please take a look at our recent publication:
Structural analysis of eight novel and 112 previously reported missense mutations in the interactive FXI mutation database reveals new insight on FXI deficiency.
Saunders RE, Shiltagh N, Gomez K, Mellars G, Cooper C, Perry DJ, Tuddenham EG, Perkins SJ. Thromb Haemost. 2009 102(2):287-301.

Have you or someone you know been diagnosed with FXI Deficiency?

The information contained on this web site is provided for scientific research purposes only. We do not give medical advice or recommend any particular treatment for specific individuals. Click here for patient information.

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Mutation Analysis
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Mutated Residue :
FXI Mutations

There are currently 192 disease causing mutations in the FXI gene compiled within this database corresponding to 487 FXI deficient patients reported in literature. Mutations are characterized with a Type I or Type II phenotype.

Type I and Type II Phenotypes
  • Type I (CRM-) is characterized by both low FXI coagulant activity (FXI:C) and low antigen (FXI:Ag). This indicates that the mutant protein is either present in lower amounts or absent in plasma suggesting that the mutation has a structural effect on the mutant protein - ie reducing translation, secretion or stabililty of FXI.
  • Type II (CRM+) is characterized by low FXI:C with normal FXI:Ag. This indicates that the mutant protein is present in normal amounts in plasma but has reduced or absent activity, suggesting that the mutation has a functional effect on the protein e.g. affecting substrate binding.

We would like to thank the Welcome Trust and MRC for financial support.
The following people worked on this project:

  • Rebecca E Saunders, UCL
  • Nuha Shiltagh, UCL
  • Prof Stephen J Perkins, UCL
  • Keith Gomez, Royal Free Hospital, London
  • Gillian Mellars, Royal Free Hospital, London
  • Carolyn Cooper, Addenbrookes Hospital, Cambridge
  • Edward G. Tuddenham, Royal Free Hospital, London
  • Dr Niamh M O'Connell, Royal Free Hospital, London
  • Dr David J Perry, Addenbrookes Hospital, Cambridge
  • Prof Christine A Lee, Royal Free Hospital, London
If you find this website useful, please reference our publication, Saunders et al, 2005. Factor XI deficiency database: an interactive web database of mutations, phenotypes, and structural analysis tools. Human Mutation. 2005. 26:192

The information contained on this web site is provided for research purposes only. All information and content on this web site are protected by copyright. All rights are reserved.