Factor VII deficiency in Beagles causing a mild bleeding disorder

Factor VII Deficiency DNA Test Submission Form

Description:
Several hereditary bleeding disorders have been identified in many different canine breeds and involve clotting (coagulation) factor deficiencies, platelet disorders, and von Willebrand disease. Coagulation factor VII (FVII) deficiency has been known to occur in Beagles for decades, but the molecular defect has only now been characterized. Affected dogs may exhibit an increased bleeding tendency following trauma or surgery or rarely appear to develop spontaneous bleeding. There are only rare reports of severe bleeding requiring blood transfusions, and some FVII-deficient dogs may remain unrecognized. As this is an autosomal recessive disorder, the diseased/mutant gene (allele) may unknowingly be passed on through generations not only via asymptomatic carriers but also affected dogs, as they may not show obvious signs. The frequency of FVII deficiency in Beagles is unknown, but affected Beagles have been recognized in the US and Canada , as well as in Europe . Furthermore, this defect also exists in Beagles used in research.

Screening Beagles with a clotting test (PT assay) may suggest FVII deficiency, but the assay must be performed on fresh (frozen) citrated plasma and does not identify carriers. Carriers have one mutant and one normal gene and appear clinically normal, but they may pass the defect to their offspring. Specific FVII activity measurements may confirm affecteds and detect carriers, but these tests are prone to errors and misinterpretation and, therefore, are rarely performed.

A mutation-based DNA test to screen Beagles for FVII deficiency has been developed through collaborative investigations at the School of Veterinary Medicine of the University of Pennsylvania and the Children's Hospital of Philadelphia . This test can clearly identify affected, carrier, and normal (clear) Beagles. We recommend testing of any Beagle with signs of bleeding, as well as its relatives. Furthermore, it may be advisable to screen any Beagle, particularly popular sires, prior to breeding to limit the spread of this bleeding disorder until information regarding frequency of FVII deficiency in this breed is available.

Charge: $75.00
Samples suitable for this DNA test include 1 ml EDTA-anticoagulated blood or 2 cheek swabs (obtained with special cyto brushes that we can provide and according to our instructions at our website http://www.vet.upenn.edu/penngen or when you request testing). For more information on canine FVII deficiency, please contact Dr. Beth Callan (215-898-5797; callan@vet.upenn.edu ) or Dr. Urs Giger (215-898-8830; giger@vet.upenn.edu ). Blood and cheek swab samples may be submitted to Dr. Urs Giger, VHUP Rm 4006, 3900 Delancey Street , Philadelphia , PA 19104-6010 . Test results are generally available within 3 weeks of receipt of samples, and all information is kept confidentially.