Introduction: Hemophilia C, or Factor XI deficiency, is a rare bleeding disorder, often identified
by prolonged partial thromboplastin time (PTT) or bleeding complications. This poster
presents two families with distinct genetic mutations related to Factor XI deficiency,
treated at the University Hospital of Halle (Saale), with varied clinical outcomes
[1]
[2]
[3].
Method: Two families with confirmed Factor XI deficiency were examined. In the first family,
two cousins underwent stem cell transplantation for beta-thalassemia major. One child
had homozygous and the other heterozygous Factor XI deficiency. Both received thrombocyte
transfusions only below standard thresholds (<10 Gpt/l or<20 Gpt/l with bleeding),
and neither had significant bleeding. The mother of one of the boys was diagnosed
with Factor XI deficiency after severe postpartum bleeding, requiring Hemoleven due
to ineffective fresh frozen plasma. To prevent complications during her second birth,
she received prophylactic Hemoleven, which led to an uncomplicated delivery. In the
second family, two children were diagnosed through routine preoperative screening
in the setting of a prolonged PTT and a family history of bleeding disorders. Both
families have consanguineous backgrounds, contributing to the higher incidence of
this rare condition.
Results: In the first family, despite homozygous and heterozygous Factor XI mutations, both
cousins had no significant bleeding, even after stem cell transplantation. In the
second family, diagnosis was incidental through preoperative screening, and no major
bleeding episodes were observed. These findings suggest that bleeding severity in
Factor XI deficiency varies, with careful monitoring and management playing a key
role.
Conclusion: These cases illustrate the variability of Factor XI deficiency, where some patients,
even with homozygous mutations, experience minimal bleeding. Early diagnosis, particularly
in families with a history of bleeding, is critical to avoid complications. Consanguinity
increases the prevalence of this rare disorder.
