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Published on: September 9, 2012
A molecular genetic study of factor XI deficiency
J F Hancock1, K Wieland, R E Pugh
1Department of Haematology, Royal Free Hospital School of Medicine, London, UK.
Blood
|May 1, 1991
Summary
Factor XI deficiency mutations vary between populations. The study found specific mutation frequencies in Jewish patients and identified undefined mutations in non-Jewish individuals, impacting bleeding risk.
Area of Science:
- Genetics
- Hematology
- Molecular Biology
Background:
- Factor XI deficiency is a rare bleeding disorder.
- Previous studies identified three mutations (Types I, II, III) in Ashkenazi Jewish populations.
- Genotype-phenotype correlations require further investigation.
Purpose of the Study:
- To investigate the allele frequencies of known factor XI mutations in a larger cohort.
- To identify undefined mutations contributing to factor XI deficiency.
- To correlate genotypes with plasma factor XI:C levels and bleeding severity.
Main Methods:
- Genotyping of 63 patients with factor XI deficiency.
- Analysis of allele frequencies for Types I, II, and III mutations.
- Comparison of mutation distribution between Jewish and non-Jewish populations.
- Correlation of genotypes with plasma factor XI:C levels and clinical bleeding phenotype.
Main Results:
- Type II and Type III mutations were frequent (44% and 31%, respectively) in the studied cohort.
- Type I mutation was absent (0%).
- 25% of mutant alleles remained undefined, predominantly in non-Jewish patients (84%).
- Significant differences in plasma factor XI:C levels were observed between genotypes.
- The II/III genotype was associated with a higher risk of severe bleeding.
Conclusions:
- Factor XI mutation profiles differ significantly between Jewish and non-Jewish populations.
- Undefined mutations are a major cause of factor XI deficiency in non-Jewish individuals.
- Genotype, particularly the II/III combination, influences factor XI coagulant activity and bleeding risk.
