The Canadian National
Inherited Bleeding Disorder
Department of Pathology and Molecular Medicine Queen's University
1. Hemophilia A and B
A) Factor VIII and Factor IX mutation analysis
B) Carrier diagnosis
C) Prenatal testing
2. von Willebrand Disease
A) Analysis for Type 2N VWD
B) Confirmation of type 1C, 2A, 2B or 2M VWD
C) Mutation analysis and prenatal testing for type 3 VWD
3. Rare Bleeding Disorders (including)
A) Factor V
B) Factor VII
C) Factor X
D) Factor XI
E) Factor XIII
Only tests for Hemophilia A, B, and von Willebrand disease are authorized by our current laboratory licence. Rare bleeding disorder testing may be performed on a research basis.
REASONS FOR REFERRAL
For quantitative disorders (hemophilia A, hemophilia B, type 1C and type 3 VWD, and rare bleeding disoders) a clotting factor level is required.
For qualitative disorders (type 2A, 2B, 2M VWD), VWF:Ag and VWF activity (VWF:RCo, VWF:GPIBM, etc.) must be provided. For some cases, VWF multimer analysis, RIPA and/or a desmopressin study may be required.
We do not accept referrals for undiagnosed bleeding disorders.
DNA or whole blood is sent to the lab at Queen’s University. Genetic analysis is performed by Sanger sequencing of the coding region of the gene of interest.
For severe hemophilia A, intron 22 inversion analysis is performed by inverse shifting PCR.
TURN AROUND TIMES AND REPORTING
The average time for test reporting for affected patients is approximately 2-3 months from the time of sample submission.
If the family-specific mutation is known, urgent reporting can be completed within several weeks. STAT testing for rare bleeding disorders is not available.
Carrier testing for females with an unknown family history may take 3-6 months. in these cases provisional reports may be issued prior to final confirmation.
For some patients, mutations are not immediately identified and in these cases the search for the causative genetic change may take several months.
Reports will only be issued to caregivers listed on the requisition forms.