A specific variant of the human leukocyte antigen B58, HLA-B*58:01, is associated with severe cutaneous adverse reactions (SCAR) to the medication, allopurinol.
The presence of this variant indicates that a person is at increased risk of a hypersensitivity reaction to allopurinol.
This test has a role in identifying patients who may benefit from avoiding a specific drug or dose, but it provides little useful information for people (including relatives) who are not taking the medications of concern. Testing of relatives is generally not recommended.
Analysis of the gene sequence of the HLA-B genes for the presence of this specific variant.
Requesting the test
This test can be requested by any medical practitioner.
4 mL blood in EDTA. Specimens may be collected by the requesting practitioner or at any Sonic Healthcare collection centre (see link below).
To help ensure the quality of the test, a genetic test should be done with a dedicated sample whenever possible i.e. a sample collected specifically for that test rather than a sample that is used for multiple tests.
We recommend that the patient or another adult check the labelling of request forms and sample tubes.