Urate-lowering

Allopurinol

The genotype here is checked before the first dose and never again, and what it predicts is not how well the drug works but whether it is safe to start. It is also the clearest case on this site of a test that only makes sense for some populations.

What this drug connects to

The genes involved

HLA-B

Gout →

The HLA-B*58:01 allele is associated with a substantially increased risk of severe cutaneous adverse reactions to allopurinol — Stevens–Johnson syndrome, toxic epidermal necrolysis and DRESS. CPIC published a guideline for HLA-B genotype and allopurinol dosing and confirmed in its 2015 update that the original recommendation stands. Allele frequency varies widely between populations, which is why testing guidance is population-specific rather than universal. This is a safety check before prescribing, not a dosing adjustment and not something to act on from a raw data file.

CPIC guidelines for HLA-B genotype and allopurinol dosing: 2015 update (Clin Pharmacol Ther 2016, PMID 26094938).

Variants MyGeneLog reports for these genes

These are the positions in your own file that carry the genes above. Not every gene in a guideline is one we report — where that is the case the gene appears above without a variant here, and the note says so.

Crohn's disease

HLA-B · rs114985235

HIV-1 control

HLA-B · rs2523590

HIV-1 control

HLA-B · rs2395029

This page is educational and contains no dosing information. Where a clinical guideline covers one of these gene-drug pairs it is written for prescribers and works through validated algorithms alongside clinical monitoring. Nothing here is a reason to start, stop, or change a medication — that conversation belongs with the clinician or pharmacist managing your treatment.