Origin of pathogenic variant and mosaicism in families with a sporadic case of haemophilia B.
Annika MårtenssonAnna LetelierEric ManderstedtHeidi GlosliRolf C R LjungPublished in: Haemophilia : the official journal of the World Federation of Hemophilia (2024)
The origin of the pathogenic variant in sporadic cases of haemophilia B is most often found in the X-chromosome derived from the maternal grandfather or, less often, from the maternal grandmother. Mosaic females seem to be found at the same frequency as in haemophilia A but at a lower percentage of the pathogenic variant.