Abstract Number: PB0700
Meeting: ISTH 2021 Congress
Theme: Hemophilia and Rare Bleeding Disorders » Rare Bleeding Disorders
Background: Hereditary factor XI (FXI) deficiency is a rare bleeding disorder caused by mutations in the F11 gene, also called hemophilia C, and is autosomal recessively inherited. To date, more than 220 mutations in the F11 gene have been identified in patients with FXI deficiency.
Aims: The aim of this study is to determine the phenotype-genotype relationship of our patients diagnosed with hereditary Factor XI deficiency in our clinic.
Methods: Patients with factor XI activity below 20% were accepted as severe factor XI deficiency. Those with 20-70% factor XI activity were considered as mild factor XI deficiency. Families were informed about genetic transmission and family screening was performed. Approval was obtained from the ethics committee of our hospital for this study. Factor F11 gene mutation was studied in 14 families.
Results: In our clinic, hereditary factor XI deficiency was detected in 255 patients. Eighty-five of our patients were diagnosed with severe factor XI deficiency. Ten patients were evaluated as homozygous and four patients were evaluated as compound heterozygous. 30 of the family members were heterozygous. 58 mutant alleles were detected in 44 patients in total. 23 of the patients were male and 21 were female. The most common mutation was p. Ala109Thr and was found in 71% (41/58) of the mutated alleles. The second most common mutation, p. Ala43Thr, was found in 9% (5/58) of the mutated alleles. The third most common mutations were with p. Glu135Ter, c.325 + 1G˃A, p. Thr150Met, p. Phe61Cys, p. Thr208Lys and p. Thr60, each of which was found in 3.3% (2/58) of the mutated alleles. Cleft palate and cleft lip were detected in one patient.
Conclusions: Eight different mutations were identified in 14 families with severe inherited FXI deficiency. In this study, p.Ala109Thr frequency of mutations in 71%, has been found at high frequency in the northern region of Turkey.
To cite this abstract in AMA style:
Albayrak C, Albayrak D, Gürkan H, Demir S. Phenotype-Genotype Relationship in Patients with Hereditary FXI Deficiency [abstract]. Res Pract Thromb Haemost. 2021; 5 (Suppl 2). https://abstracts.isth.org/abstract/phenotype-genotype-relationship-in-patients-with-hereditary-fxi-deficiency/. Accessed October 2, 2023.« Back to ISTH 2021 Congress
ISTH Congress Abstracts - https://abstracts.isth.org/abstract/phenotype-genotype-relationship-in-patients-with-hereditary-fxi-deficiency/