Categories
Gene

HFE

HFE-Associated Hereditary Hemochromatosis

It is the responsibility of the ordering physician to ensure that informed consent has been obtained from the patient/legal guardian before ordering genetic testing. Please review the following Pre-Test Counselling Information with your patient before requesting any of our genetic tests.

Clinical Features

Please refer to the BC Ministry of Health Guidelines and Gene Reviews for detailed background on the clinical features of HFE-HH.

Genetics

Please refer to the BC Ministry of Health Guidelines and Gene Reviews for up-to-date information regarding the genetics of HFE-HH.

Indications for Testing

Genetic testing for HFE-HH is performed in accordance with BC Ministry of Health Guidelines.

There have been logistical changes to the ordering and laboratory algorithms (figures 1 and 2) that are not reflected in these Guidelines; the ordering algorithm (figure 1) has been updated here:

Changes to the approach to ordering

Please see HFE-HH Ordering Algorithm

All testing for HFE-HH should be ordered with the Standard Outpatient Laboratory Requisition (SOPLR), using the appropriate indications box under HFE-Hemochromatosis, as outlined in the algorithm.

The MGL general requisition is no longer used to order this test.

Changes to laboratory algorithm

Collection/Chemistry laboratories should follow their site-specific process for collection and processing, as established in consultation with BC chemistry laboratories and MGL.  This algorithm essentially follows figure 2 from the BC Ministry of Health Guidelines, with minor changes.

Description of this Assay

The C282Y mutation is detected by PCR-based RFLP analysis; this assay will not detect other rarer HFE alleles, including the H63D variant.

Sensitivity and Limitations

A negative result does not definitively exclude the possibility that the individual has HFE-HHC.  The H63D mutation and other rare HFE mutations are not included in this assay; neither are mutations in other genes linked to hemochromatosis. The residual risk following a negative result will vary depending on the indication for the test.

Given the significantly reduced penetrance of this condition, care must be taken when counselling pre-symptomatic individuals. This test cannot determine who will and who will not eventually develop clinical disease.

Turnaround Time

Routine

3 weeks

Specimen Requirements

Blood: 0.5 – 4 mL EDTA

Label each sample with three patient identifiers; preferably patient name, PHN, and date of birth and ship to the address below. Samples should be shipped at room temperature with a completed MGL Requisition to arrive Monday to Friday (not on Canadian statutory holidays). 

Test Price and Billing

Testing is only available to residents of Canada, except in very specific circumstances where testing is urgent or emergent.  Payment is not required when requests are made for individuals who are insured by Health Insurance BC (administered through the BC Medical Services Plan (MSP)) AND eligible for testing according to the test utilization guidelines / policy. If the individual undergoing testing is not insured by these providers or does not meet utilization guidelines or policy, please complete a billing form; testing will only commence after receipt of billing informationTest prices can be found here.

Cautions

Molecular genetic testing is limited by the current understanding of the genome and the genetics of a particular disease, as well as by the method of detection used. This method will not detect all mutations (e.g., mutations outside the regions tested as described above, large genomic deletions, promoter mutations, regulatory element mutations).

Rare single nucleotide variants or polymorphisms could lead to false-negative results. If results obtained do not match the clinical findings, consult the on-service Molecular Geneticist.

A previous bone marrow transplant from an allogenic donor will result in molecular data that reflects the donor genotype rather than the recipient (patient) genotype. Consult the on-service Molecular Geneticist for approach to testing in such individuals.

Transfusions performed with packed red blood cells will generally not affect the outcome of molecular genetic testing. However, if there is no clinical urgency, the cautious approach is to wait one week post packed red cell transfusion before collecting a sample for genetic testing. Consult the on-service Molecular Geneticist as needed.

Test results should be interpreted in the context of clinical findings, family history, and other laboratory data. Errors in our interpretation of results may occur if information given is inaccurate or incomplete.