PROJECT OUTLINE:
GOLDEN RETRIEVER
HEMOPHILIA A STUDY
2004-2005

Background: In 2002, hemophilia A was diagnosed in 3 related Golden retriever litters. Subsequent pedigree review and familial testing indicated that hemophilia has been present and unwittingly propagated in this breed through at least 5 generations, with affected dogs identified in the United States and Canada. Hemophilia is a hereditary bleeding disorder caused by specific deficiency of coagulation Factor VIII. The trait is X-linked recessive and affected Golden retriever males have Factor VIII activity (FVIII:C) ranging from 3 to 8% of normal, causing mild to moderate clinical signs. In contrast, carrier females have normal FVIII:C and no bleeding tendency.

Study Goal: A preliminary study conducted by the Coagulation Laboratory indicated that carrier detection could be performed using a DNA marker to track the inheritance of a mutant Factor VIII gene in this breed. The goal of the current study is to limit propagation of hemophilia A in Golden retrievers through enhanced carrier detection. Genetic status of males will be determined by direct measurement of FVIII:C. Factor VIII marker pattern (DNA marker genotype) will be used to predict genetic status of suspect carrier females. Results will help differentiate dogs at risk for propagating hemophilia from related dogs (with desirable traits) that can safely be used in breeding programs.

Study Design: Our laboratory is recruiting Golden retrievers suspected of having a bleeding tendency, or dogs related to previously tested hemophilic males and carrier females. Laboratory analyses will include FVIII:C (performed on citrate plasma) and DNA isolation (from EDTA whole blood) for Factor VIII marker genotyping. The DNA marker represents normal variation in the Factor VIII gene sequence that can be used for linkage analysis of the hemophilia trait. Results and interpretation of males’ FVIII:C will be sent to participants within 3 to 4 days of sample receipt. Marker genotyping will be performed in batches every 2 to 3 weeks and results compiled within 1 month of sample receipt. This is a 1-year project supported by the AKC Health Foundation.

Participants: Participation involves submission of a blood sample and pedigree from each enrolled dog. Participation is voluntary and a signed consent form is requested with sample submission. All information identifying individual dogs will remain confidential. Dogs are assigned a study number and data for all hemophilia-affected families will be summarized anonymously. Please call Dr. Brooks (607-275-0622) if you would like to participate or discuss the project in more detail.

Sample Collection and Submission: See page 2 for detailed instructions and shipping address. Referral veterinarians can request citrate and EDTA collection tubes from the Coagulation Laboratory or use their in-house collection tubes to obtain the following samples:

Males: EDTA whole blood AND citrate plasma
Females: EDTA whole blood only

THANK YOU FOR YOUR HELP WITH THIS STUDY!

Dr. Marjory Brooks
October, 2004
Cornell College of Veterinary Medicine
Population Medicine and Diagnostic Science
Animal Health Diagnostic Laboratory
Comparative Coagulation Section
Upper Tower Road
Ithaca, New York 14853
telephone: 607-275-0622
fax: 607-275-0720
email: mbb9@cornell.edu

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INSTRUCTION AND CONSENT FORM FOR GOLDEN RETRIEVER HEMOPHILIA STUDY

Thank you for your participation in this study. Please follow instructions carefully, and feel free to call Dr. Brooks if you have any questions or wish to discuss the project in more detail (607-275-0622).

I. Sample Collection

EDTA (for DNA analyses) is submitted from all dogs entered in the study. An additional citrate plasma sample (for coagulation Factor VIII assay) is required from males.

EDTA blood (males & females)

1. Fill 1 to 2 purple top (EDTA) vacutainer tubes with blood to obtain 4 to 6 ml total sample volume
2. Store EDTA tubes in refrigerator until shipment.

Citrate plasma (males)
1. Place exactly 0.3 ml citrate into a 3 ml syringe
2. Perform venipuncture and draw exactly 2.7 ml blood into the syringe
Alternate technique: draw blood with vacutainer needle directly into a blue top (citrate) vacutainer tube
3. Centrifuge the citrate whole blood sample for 10 minutes
4. Draw off citrate plasma and transfer to a plastic shipping tube
5. Store plasma tube in freezer until shipment

II. Shipping (PLEASE ENCLOSE PEDIGREE & SUBMISSION FORM WITH SAMPLES)

Ship whole blood and citrate plasma samples in a styrofoam box with frozen cold packs. Ship for overnight (24 hour) delivery.

III. Owner's Authorization

I authorize collection of blood samples (5 to 10 ml or 2 tsp. total volume) from my dog for the purpose of DNA and Factor VIII analyses in order to study the genetic basis of hemophilia A in Golden retrievers.

PLEASE RETURN THIS FORM WITH SAMPLES, PEDIGREE & SUBMISSION FORM IN SHIPPING CONTAINER. CALL DR. BROOKS AT 607-275-0622 IF ANY QUESTIONS