What Your Test Results Mean:

Carriers typcially show no symptoms of this disorder; however, carriers are at an increased risk for having a child born with factor XI deficiency. Risk for current or future pregnancies is dependent on your partner’s carrier status. Consulting with a genetic counselor as well as carrier testing of your partner is recommended.

Disease Explained:

Factor XI deficiency rarely causes spontaneous bleeding like other forms of hemophilia do, but individuals may have excessive bleeding during surgical operations. It is important for doctors to know about this condition ahead of time so that they can pre-treat the surgical patient with a plasma transfusion to prevent extreme blood loss.

How the Genetics Works:

Factor XI is an autosomal recessive blood disorder caused by pathogenic variants in the F11 gene. In general, individuals have two copies of the F11 gene. Carriers of factor XI deficiency have a single variant in one copy of the F11 gene while individuals with factor XI deficiency have variants in both copies of their genes, one inherited from each parent. Risk for two carriers to have a child with the disorder is 25%.