Other names: Christmas disease, Factor IX deficiency
Gene affected: F9
Inheritance: Recessive, linked to the X chromosome
Mutation: CanFam3.1    X    g.109530868G>A    c.731G>A
* In hereditary genetic diseases linked to the X chromosome, the following rules apply:
-For a recessive disease, the male is affected (at risk for developing the disease) even if he has only one copy of the mutation.
-Male-to-male transmission doesn't exist, since a male never passes on his X chromosome to his sons.
-All females of an affected male will inherit the mutant gene.
-Females who are carriers have a 50% chance of passing the mutant gene to their sons and daughters.
OMIA link: 000438-9615

Breeds suitable for testing : Rhodesian Ridgeback

References:
Mischke R, Kühnlein P, Kehl A, Langbein-Detsch I, Steudle F, Schmid A, Dandekar T, Czwalinna A, Müller E. G244E in the canine factor IX gene leads to severe haemophilia B in Rhodesian Ridgebacks. Vet J. 2011 Jan; 187(1):113-8. [PubMed: 20303304]