- All samples referred for Haemophilia A genetic testing must be accompanied with information regarding the inheritance of this trait in the patient's family.
- All prenatal samples referred for Haemophilia A genetic testing must be accompanied by maternal bloods for DNA extraction (collection details as below).
- Prior work-up of the mutation within the relevant family is preferable before refering prenatal samples for analysis.
Note: All samples should be forwarded to LabPlus at room temperature within 24hours.
9 mL CPD Blood (Preferred) 9 mL EDTA Blood Prenatal Amniotic Fluid Prenatal Chorionic Villus Turnaround Time: Within 4 weeks Diagnostic Use and Interpretation
This test is used to establish the genetic basis of haemophilia B. These results are useful for the confirmation of haemophilia B and in prenatal and carrier studies of haemophilia B.
For information about Haemophilia A genetic testing:
Haemophilia A genetic testing
To contact the Molecular Haematology team please call:
Auckland City Hospital (09) 307 4949 Lablink ext 22000 Prof. Peter Browett (Haematologist) ext 9090-86281 Nikhil Ghallayan (Section Leader) ext 22006 Molecular Haematology Lab ext 22005
For more inforamtion about the Molecular Haematology service at LabPLUS:
Molecular Haematology information page
Used for prenatal and carrier studies of haemophilia B. Haemophilia B is caused by reduced levels of activity of the factor IX blood coagulation protein. Mutations within the factor IX gene responsible for causing haemophilia B are very heterogeneous.
Haemophilia B is an X-linked, recessive disorder. The segregation probabilities are thus 50% for each carrier female to transmit the defective gene to each child, male or female, while a hemophiliac father will only have normal sons and carrier daughters.
Carrier detection and prenatal diagnosis are ideally performed by direct detection of the DNA defect in the factor IX gene.
The factor IX defects in virtually all the haemophilia B families in New Zealand have been identified and can thus be used for direct analysis (specific mutation for each family is kept on file).
For de novo cases or haemophilia B families where the defect is unknown, direct sequencing of the entire coding region of the factor IX gene must be performed.
Van de Water et al Haemophilia 2, 24-27; 1996