Family History and Genetic Mutation

Family History

The majority of male Registry participants across all severity levels and hemophilia types had a family history of hemophilia. Of the male participants with hemophilia A, a family history of hemophilia was present in 71%, not present in 23%, and unknown in 6%. Among participants with hemophilia B, a family history of hemophilia was present in 78%, not present in 17%, and unknown in 5%.  For both hemophilia A and B, a slightly lower percentage of males with severe hemophilia reported a family history in comparison to those with moderate or mild hemophilia (Figures 20 and 21).

Figure 20. Family history of hemophilia among male Registry participants with hemophilia A, by severity
Figure 20. Family history of hemophilia among male Registry participants with hemophilia A, by severity

Figure 20. Family history of hemophilia among male Registry participants with hemophilia A, by severity
Mild Moderate Severe
Yes 1,326 79.3% 982 77.8% 2,829 65.9%
No 252 15.1% 211 16.7% 1,186 27.6%
Unknown 95 5.7% 69 5.5% 281 6.5%
Figure 21. Family history of hemophilia among male Registry participants with hemophilia B, by severity
Figure 21. Family history of hemophilia among male Registry participants with hemophilia B, by severity

Figure 21. Family history of hemophilia among male Registry participants with hemophilia B, by severity
Mild Moderate Severe
Yes 347 80.1% 607 85.3% 517 69.8%
No 62 14.3% 71 10.0% 188 25.4%
Unknown 24 5.5% 34 4.8% 36 4.9%

Genetic Mutation

Among male Registry participants with hemophilia, the specific genetic mutation causing their hemophilia was unknown for 45% known for 37%, and information about genetic mutation information was not available for 18%.  As the severity level increased, it was more likely that the specific genetic mutation causing the hemophilia was known; among participants with mild, moderate, or severe hemophilia, the mutation was known for 30%, 33%, and 42%, respectively (Figure 22).

Figure 22. State of knowledge of specific genetic mutation among male Registry participants with hemophilia
Figure 22. State of knowledge of specific genetic mutation among male Registry participants with hemophilia

Figure 21. Family history of hemophilia among male Registry participants with hemophilia B, by severity
Mild Moderate Severe
Known 630 29.9% 657 33.3% 2,122 42.1%
Not Known 1,109 52.7% 934 47.3% 2,045 40.6%
No Information Available 367 17.4% 383 19.4% 870 17.3%