Sex-linked recessive: hemophilia A

The pedigree chart of Queen Victoria of England illustrates inheritance of hemophilia A. Queen Victoria herself was a carrier due to a chance mutation. Her children married other royalty and passed the trait throughout the royal families of Europe.

The pedigree below has been generously provided by Janet Stein Carter, biology instructor at Clermont College, University of Cincinnati, who retains copyright.

Hemophilia A: Queen Victoria's pedigree